Operations in Korea

8/7/2019 Operations in Korea

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THE COMMAND AND GENERAL STAFF COLLEGE

LIBRARY

9 5 U 9U5750Call Number y2J25i;2"~FL F orm 887 (R ev) 22 Oct 52USACGSCP2-427715 June 625M


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OPERATIONSIN

KOREA

D E P A R T M E N T O F MILITARY ART A N D E N G I N E E R I N G U N I T E D S T A T E S MILITARY ACADEMY

W E S T P O I N T , N E W Y O R K


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on

OPERATIONSIN

KOREA

DEPARTMENT OF MILITARY ART AND ENGINEERINGUN ITED STATES MILITARY ACADEMY

WEST POINT, NEW YORK1953

NOV 5 1951;RESTRICTED


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U. S. M. A. A. G. PR INT ING OF FIC EWE S T POINT NEW YORK

Fe bru ary , 1953 600


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CONTENTS

PAGEINTRODUCTION 1Strategic Importance of Korea . 1Political Background of the War 2Theater of Operations 3Plans and Opposing Forces 3

North Korea 3South Korea 4

OPERATIONS 5The United Nations Defensive, 27 June-15 September 1950 . . 5

Reaction of the United Nations 6The Delaying Action . 7Defense of the Pusan Perimeter 12

The United Nations Offensive, 16 September-2 November 1950 . . 16The Amphibious Landing at Inchon . 16Breakout From the Pusan Beachhead 18The Advance to the Manchurian Border 20

The Chinese Communist Intervention,3 November 1950-24 Ja nu ary 1951 21

Operations on the X Corps Front 24Operations on the Eighth Army Front 26The Second Invasion' of South Korea 29

The Fi rs t United Nations Counter offensive, 25 January- 21 Apri l 1951 31Operation Thunderbolt 3iThe Communist Counterattack 32Operation Ripper . 3 3The Advance Beyond the 38th Parallel 34

The Chinese Communist Forces Spring Offensive,22 April-8 July 1951 35

The Fir st Impulse of the Offensive 36The Lull Between Impulses . . . 3 7The Second Impulse of the Offensive 38


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C O N T E N T S

PAGEThe Counterattack . 4 0The Advance to the "Iron Tria ngle " 41

The Period of Arm istice Talks 43COMMENTS . 4 7

Tactics 47Enemy . 47American 47

Air ( Power 48Naval Support 49Reason for Am erican Pa rticipation 50


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Security Information

OPERATIONS IN KOREA

INTRODUCTIONSTRATEGIC IMPORTANCE OF KOREA (Map 1).

After W orld War II the western strategic frontier of the Americaswas established along the great arc extending from Alaska throughthe Aleutians, Japan, Okinawa, Formosa, the Philippines, and theMarianas.During the postwar period Russian influence was extended eastward to include domination of China, Manchuria, and the northernhalf of Korea. As a resu lt of agreem ents reached at the Yalta Conference early in 1945, Russia acquired the southern half of SakhalinIsland, making tha t island Soviet terr ito ry in its entirety . The Kurile Islands, just northeast of the Japanese island of Hokkaido, wereoccupied by Russian forces between 8 August and 1 September 1945.With the Japanese link in our chain of defense already threatenedfrom the north, the strategic importance of Korea increased materially. With the Communists already in the Kuriles, Sakhalin, Siberia, and Manchuria, their possession of South Korea would leaveJapan open only to the east. Thus the integrity of our defensivearc would be threatened, and Russia's strategic position in northeastern Asia would be further strengthened. "T he Korean peninsulawould provide a buffer for richly endowed Manchuria and the portcity of Vladivostok, eastern terminus of the Trans-Siberian Railroad and important Soviet air and naval base. Possession of theentire peninsula would seal off the Sea of Japan and would provideair bases and ice-free naval bases that would facilitate military operations against Japan.1

Conversely, the Korean peninsula in neutral or friendly handswould constitute a shield between Manchuria and our island frontierand would secure Tsushima Strait and the southern portion of the1 The distance across the Tsushima Strait between Pusan and Kyushu or southern Honshu is about the same as that from southern England to thebeaches of Normandy.

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Sea of Japan. In case of necessity it could furnish convenient basesfor air and naval operations against Vladivostok and against Manchuria and the other northern provinces of China.*POLITICAL BACKGROUND OF THE WAR

In the Cairo Declaration, December 1943, the United States, theUnited Kingdom, and China pledged that "mindful of the enslavement of the people of Korea . . in due course they shall becomefree and independent." The pledge was reaffirmed in the PotsdamDeclaration of Ju ly 1945 and was subscribed to by th e Soviet Unionwhen she entered the war against Japan.At the end of World War II the 38th parallel was designated as atemporary line of demarcation to facilitate the surrender of Japanese troops in Korea. Japanese forces nor th of the parallel surrendered to the Soviet troops, and those south capitulated to .UnitedStates forces. At no time did the United States contemplate th atthe 38th parallel would permanently divide the country. 0W*>;!r< ;On the other hand r the Russian occupation authorities soon established frontier outposts and patrols and halted passage across theparallel. Repeated efforts by our representatives failed to eliminate' this artificial obstacle to the political and economic unity of the nation.The next development was the Moscow Agreement2 of December1945, which aimed at establishing a provisional Korean democraticgovernment; however, every attempt to implement this agreementwas thwarted by the Soviet Union./ Thereupon the United Stateslaid the problem of Korean unity and independence before the UnitedNations. A tem porary commission was established by th is worldbody to supervise the election of Korean representatives who woulddraft a democratic constitution and establish a national government.But Russia, busily engaged in sovietizing the Korean people northof the 38th parallel, refused entry to the United Nations Commission. Nevertheless, free elections were held in South Korea on 10May 1948; and the Republic of Korea was founded on 15 August1948.

Communist rule above the parallel was formalized on 9 September1948 by the inauguration of the People's Democratic Republic ofKorea. Thus the 38th parallel, "a fortuitous line resu lting from theexigencies of the war", had become a politicalfrontier.2 The United States, Russia, and the United Kingdom participated; China subsequently subscribed.


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From this time until the invasion of June 1950 the Communist-sponsored North Korean Government tried every means short offull-scale war to foster disunity and disorder in the new republicsouth of the parallel. Border raids, guerrilla action, sabotage, propaganda, and economic strangulation all failed to achieve these ends.THEATER OF OPERATIONS (Maps 2a and 2b)The Korean Peninsula, about 575 miles long and averaging about^150 miles wide, is similar in shape but larger than the state ofFlorida.Korea, for the most pa rt, is mountainous. A grea t chain of mountains extends south along the east coast almost to Pusan, with thehighest peaks in the north. South of the 38th parallel this rangethrows off a spur which runs diagonally southwest across SouthKorea to the Yellow Sea in the vicinity of the port of Mokpo. Thewest coast is characterized by numerous estuaries and indentations.Farther inland are rice paddies, lowland flats, terraced slopes, hills,and broad valleys. Though far from ideal for large-scale ground operations, western Korea is, nevertheless, more suitable than themountainous area to the east.The main rivers, most of which run south and west, are very broadand sufficiently deep to impede military operations. Their effect ismultiplied during the rainy season.Prior to the outbreak of hostilities the standard-gauge rail network, single-tracked for the most part, provided reasonably good^transportation facilities between the principal ports and cities. Inthe north it connected with the Manchurian railway system . Thehighway system, however, was very inadequate for motor vehicles.Most of the roads were narrow and tortuous. A few were hard-surfaced, and some were surfaced with gravel or crushed rock; butmost of them were ordinary earth roads. Air transporta tion washampered by a dearth of satisfactory airfields and emergency landing facilities.The climate of Korea is similar to th at of the region between Georgia and Maine in the United States. W eather conditions interferewith military operations during the cold winter of the northern regions, during the spring thaw in February and early March, and during the pronounced rainy season of July and August.PLANS AND OPPOSING FORCESNorth Korea.In the early days of Soviet occupation Communistpropaganda had indicated that the objective of North Korea was to


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drive out the "American imperialists" by force; th a t is, to seize andhold South Korea. In December 1948 Russia announced th a t shehad withdrawn her occupation troops from North Korea, but theUnited Nations Commission was not permitted to verify this.


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100,000 small arm s (including rifles, pistols, and machine guns) andapproximately 50,000,000 rounds of ammunition; more than 2,0002.36-inch rocket launchers (bazookas) and over 40,000 rounds ofammunition; more than 4,900 vehicles of all types ; and a large number of 37-mm. and 57-mm. anti tank guns, 105-mm. howitzers, 60-mm.and 81-mm. m ortars , together w ith over 700,000 rounds of amm unition for these weapons. In addition, seventy-nine light naval craftand twenty liaison aircraft of the L4 and L5 type were turned overto the South Koreans.Prior to the end of the occupation Republic of Korea (ROK) forceshad been further provided with 40,000 Japanese rifles and stocks ofsuitable amm unition. Subsequent to the American withdrawal individual organizational equipment for 15,000 troops was transferredfrom stocks in Japan.Further assistance was planned under tjie terms of the MutualDefense Assistance Act of 1949, but the implementation of this planhad scarcely begun when the conflict broke out.The plans of the Republic of Korea Army, besides providing forinterna l security, were designed solely to defend the country agains tinvasion from the north . The Army was to fight a delaying actipnfrom the 38th parallel south to Pusan, hoping meanwhile for frieiidlyintervention.'At the time of the invasion the Republic of Korea Army, whichnumbered 100,000, consisted of eight divisions,4 only four of whichwere deployed along the frontier. A sizable proportion of the Armystrength was engaged in suppressing guerrillas. The South Koreanspossessed no tanks, no medium or heavy artillery, and none of thesupporting services normal to American divisions. Six of the e ightdivisions had only one battalion each of 105-mm. howitzers; theother two divisions had no field artillery. Equipped largely w ithwhat the United States had transferred, the Navy consisted of ahandful of patrol craft, while the Air Force did not possess a singlewarplane.

OPERATIONSTHE UNITED NATIONS DEFENSIVE,27 JU NE-15 SEPTEMBER 1950 (Map 3)At 0400 on' Sunday, 25 June 1950, the North Korean People'sArmy, commanded by Marshal Choi Yung Kun, invaded the Repub* The ROK division was patterned in general after the American division, eventhough its strength was only about 9,500,


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6lie of South Korea. The main effort, conducted with precision, proceeded down the Pochon-Uijongbu and Yonchon-Uijongbu corridors toward Seoul. This drive was covered on th e right by an attack thro ugh Kaesong on Munsan and on the left by a s trong movement against Chunchon. On the western extrem ity of the invasionfront the Ongjin peninsula was quickly captured, and on the eastcoast' a column advancing on Kangnung linked up with small sea-borne detachments. (By 30 June landings had been made at pointson the east coast as far south as Yongdok.) Supported by ampleartille ry and some 100 Russian-built combat planes, and spearheadedby T34 tanks, the North Korean attacking force of six divisions plusseveral brigades was too strong for the four South Korean divisionsth a t opposed it. W ith a small amount of ligh t artillery, a few armored cars, and no air support, the ROK troops were not yet readyto cope with anything more than guerrilla bands or raids across theborder. In addition, surprise was on the side of the invaders.By 28 June th e North Koreans had taken the capital city of Seoul,had closed up along the Han River from its mouth to a point abouttwenty miles east of Seoul, and had advanced as far as Samchok onthe east coast. ROK troops suffered serious losses in withdrawingsouth of the Han River; and their attempts to regroup and retainsome degree of cohesion availed little as the enemy forces continuedthe ir movement, which put them along the line Suwon-W onju-Samchok on 4 July.

Reaction of the United Nations.-Faced with its most significanttest to date, the United Nations acted both quickly and firmly. On25 June the Security Council adopted a resolution calling for the cessation of hostilities and reques ting member nations to refrain fromgiving aid to the aggressors. When this failed to stop the fighting,President Truman announced, on 27 June, tha t he had ordered American air and sea forces to give the South Korean Army cover andsupport.5Later that day the Security Council passed another resolution,which recommended that the members of the United Nations furnish such assistance to the Republic of Korea as might be necessaryto repel the armed attack and to restore international peace and security in th a t area. Responses to th is request for help includedpledges of raw materials, food and medicinal supplies, and direct5 Prior to this date General MacArthur's Far East Command had no responsibility toward Korea other than the evacuation in an emergency of UnitedSta tes nationals. Some 2,000 of these were evacuated by 28 Jun e, about870 of them being flown to Jap an .


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military support. Canada, New Zealand, the Netherlands, Australia, and the United Kingdom placed naval forces at the disposalof the United Nations.6On 30 June the President announced that General MacArthur hadbeen authorized to use American ground troops in Korea. At th istime the Eighth Army, stationed in Japan since the end of WorldWar II, consisted of four woefully under-strength occupation diviz_sions. These divisions had less than 70 per cent of their full complement of personnel and were organized with only two battalionsper infantry regiment. jSerjpus shortages existed in m ortars and recoilless rifles; and, because of the poor roads and weak bridges in

Japan, divisional tank units were equipped with M24 light tanksra ther than thp heavier tank s normally prescl'llmd. Musi Of Iheequipment in the hands of troops had been used in World Warwas worn to a degree, and in some instances was unserviceable because of a lack of maintenance p ar ts and trained technical personnel.The troops in Japan had been undergoing intensive training forsome months; but, hampered by the duties of occupation and by ascarcity of maneuver areas in Japan for units larger th an a battalion,their combat readiness was far from complete. However, a series ofcommand-post exercises had been conducted for division and higherheadquarters. These headquarters were able to act quickly and effectively when orders were received for the commitment of groundforces in Korea.In order to make the most effective use of th e various United Nations forces, the Security Council adopted a resolution on 7 Julywhich provided for unified command in Korea. The United Stateswas requested to designate a commander in chief. The followingday the President appointed General MacArthur.7

The Delaying Action.The problem which confronted GeneralMacArthur at the end of June was to employ the ground, sea, andair forces available to him in a delaying action so as to provide thetime required to build up in South Korea a force capable of ejectingthe aggressors.One of the initial steps was the dispatch to Korea of a group knownas the GHQ Advanced Command Group (ADCOM), headed by Briga6 In addition, the Australian Government made available a RAAF fighter squadron; and Canada provided some air transports for use between the westcoast of the United States and Japan.7 Throughout this period the Soviet delegate to the Security Council was absent,the Soviet Union having boycotted meetings of the council since 10 January 1950.


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8dier General John H. Church. This group functioned from 27 Juneuntil it was absorbed by Headquarters, United States Armed-Forcesin Korea (USAFIK) on 3 July . It performed valuable service in beginning the reorganization of shattered ROK forces, in keepingTokyo advised of the front-line situation, and in expediting the delivery of vital supplies to ROK forces.8The Far East Air Forces,9 flying from bases in Japan, began operations against the North Koreans^bn 27 June. On 28 June a restriction which limited air operations to South Korea was lifted.Enemy air opposition was soon virtually eliminated, and close-support and interdiction missions contributed materially to retardingthe advance of the North Korean ground forces.After neutralizing the small North Korean Navy, the UnitedStates Naval Forces in the Far East10 and other United Nationsnaval elements established an effective blockade of the entire Koreanpeninsula. In addition, they provided water tran spor t and escort oftroops and equipment to Korea and commenced interdiction operations by surface ships and carrier aircraft against coastal lines ofcommunication.

The prompt application of sufficient ground strength to slow theinvasion posed difficulties with which the air and sea forces did nothave to contend because of their greater relative strength and theirstra teg ic mobility. Stated briefly, the problem was to move Arm ytroops and supplies across the 125 miles of water separating Japanfrom the port of Pusan; thence 175 miles by difficult, winding roadto Taejon; and, finally, 100 more miles toward Seoul. Expansion andimprovement of the po rt and the establishment of adequate base facilities had to be accomplished at the same tim e.Advance elements of the American 24th Infantry Division; commanded by Major General William F. Dean,11 arrived in Korea on 2July; and a small task force (Lieutenant Colonel Charles B. Smith)8 By 29 June approximately 5,600 tons of supplies for Korea had been loaded onships in Japan, and 119 tons of emergency supplies had been sent by airto Pusan.9 Lieutenant G eneral George E. Stratem eyer commanding. Before the invasionof South Korea the Far East Air Forces, consisting of eight and a halfcombat groups, was charged with the air defense of Japan, Okinawa,Guam, and Philippines.10 Vice Admiral Charles T. Joy Commanding. The principa l element of theseforces was the Seventh Fleet, commanded by Vice Admiral Arthur D.Struble.11 On 3 July General Dean was designated commander of the United States* Forcesin Korea. The advance force was air transported from Kuyushi to Taejon.


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composed of two companies of infantry, a battery of artillery, two4.2-inch mortar platoons, a platoon of 75-mm. recoilless rifles, andsix 2.36-inch rocket-launcher teams was sent forward to make contac t with the enemy. Soon afterwards the remainder of the divisionlanded and moved forward. Lieu tenant General Walton H. Walkerbecame ground commander in Korea on 12 July, and on the following day his Eig hth Arm y head quarters was established the re. On16 July the Eighth Army assumed command of all ROK groundforces..Task Force Smith established light-patrol contact with the enemyon 4 July . Early the next day it received the full impact of an enemydivision th a t was supported by more tha n th irty T34 tanks . Although heavily outnumbered and outgunned, the small delayingforce held off the attackers for four or five hours, after which it wasforced to abandon all but the men's individual weapons and fight itsway back. The pa ttern for subsequent North Korean attac ks wasestablished here: a strong frontal attack followed by an envelopment of both flanks and the establishment by infiltrating groups ofroad blocks on the supply roads.

It soon became apparent that the main enemy thrust was beingmade down the Seoul-Taejon axis with about three reinforced divisions. The 24th Division, after executing several costly but successful delaying actions between Osan and Taejon, was compelled toyield th a t communications center on 20 July.12 In spite of the overwhelming superiority of the North Koreans, they did not succeed inpreventing the orderly withdrawal of the American troops.. Although the initial employment of the 24th Division was necessarilypiecemeal, it caused the enemy to slow his advance by frequent andsometimes unnecessary deployment of large numbers of troops.

In the mountainous central sector and along the east coast, resistance was being offered solely by the regrouped and reorganizedrem nan ts of approximately five South Korean divisions. However,the American 25th Infantry Division (Major General William B.Kean), having completed its movement to Korea by 14 July, advanced into th is broad sector. By 22 July the division was concentrated in the Sangju area, and on the next day it relieved two EOKdivisions along a twenty-five-mile front extending southwest fromHam chang. North Korean advances in this central sector, particu12 It was after this operation that General Dean was reported as missing' in action. On 23 July, General Church succeeded him as comm anding generalof the 24th Division. It was also in this operation t ha t the new 3.5-inchrocket launcher, firing an eight-pound shaped charge, was first used.


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10larly down the Chungju-Hamchang corridor, now threatened thevital Taejon-Taegu supply link and the right flank of the Americanposition immediately east and north of Yongdong.

The strongest enemy a ttack s continued to be made along the axisTaejon-Yongdong, against the ba ttered 24th Division. This division was relieved on 22 July by the Am erican 1st Cavalry Division13(Major General Hobart R. Gay), which had landed at Pohang on 18July . Both the 1st Cavalry Division and the 25th Infantry Division,on its righ t, fought stubbornly in one delaying position after ano theragainst greatly superior stren gth . By the end of the month the twodivisions were facing the North Koreans along an interrupted linefrom south of Kumchon to north of Hamchang.Meanwhile a North Korean force of two divisions drove rapidlysouth along the west coast toward Chonju. Opposed only by weakelements of the South Korean militarized police, these columnsreached Kwangju and the southwestern port of Mokpo by 25 July.Turning east, the enemy pushed toward Chinju and Umyong. General Walker, having recognized this maneuver as a strategic envelopment of major proportions, took immediate steps to counter it.Two newly arrived battalions of the American 29th Infantry Regiment were committed in the Chinju area; and the 24th Divisionmoved rapidly south from Kumchon, deployed leading elements, andmade contact with the enemy on 27 July in the vicinity of Anui andHadong. After five days of heavy fighting at various points along aforty-mile front the division had withdrawn by 1 August to thebroken line shown on the map. But there was no respite; the thr ea tto the vital port of Pusan grew as the enemy committed more andmore strength in tha t direction.On 31 July the 25th Division crossed the Naktong at Waegwanand, in a move of unprecedented speed, shifted from the northernto the southern sector of the front in two days' time to protect theapproaches from Chinju to Pusan . On 1 August the 1st CavalryDivision crossed the river at Waegwan, and by the next day all theNaktong River bridges had been blown. The Naktong phase of theoperations had begun.

By 5 August the 25th Division had taken over the sector runningsouth from the junction of the Naktong and Nam Rivers. The 24thDivision and the 1st Cavalry Division had already completed theirwithdrawal to organized defensive positions east of the Naktong,and ROK divisions assumed responsibility for the northeastern sec13 One battalio n of the 7th Regiment remained in the Yongdok area to streng thenROK resistance against the push down the east coast.


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11tor of the defensive perimeter. Unrem itting enemy pressure ha d.squeezed the defending American and ROK units into a rectangular-shaped beachhead ninety miles long by sixty miles wide. Untilnow the line of battle had been in no sense continuous, and even atthis time there was a wide mountainous gap between Andong andYongdok.

Identifications indicated that at least thirteen North Korean infantry divisions and one armored division were now attack ing . Thesedivisions were supported by artillery fire that was both intense andaccurate.From the beginning of the conflict most of the N orth Korean armswere provided by Russia. In spite of Russian claims that no arm shad been furnished North Korea since the end of the occupation, December 1948, many captured articles were identified as having beenmanufactured as late as 1950. Among these were items of signalequipment, amm unition, and autom atic weapons. Other equipmentof Russian manufacture included artillery, mortars, small arms, andtanks.To oppose the many enemy divisions, General Walker had threeAmerican divisions, all considerably under strength, and five ROKdivisions. The lat ter had recently been reorganized and re-equipped.As previously mentioned, the new 3.5-inch rocket launchers hadbeen in use in limited numbers since 20 July; but the first mediumtanks did not a rrive until 30 July.Although in the first week of August the situation of the defenders was still grim, there was reason to be somewhat more hopeful.The enemy had suffered an estimated 37,000 casualties; we still helda beachhead tha t afforded ample room for m aneuver; and Pusan provided a port with adequate facilities.14 The Pusan Logistical Command (Brigadier General Crump Garvin) had been organized on 4July and during that m onth had discharged over 300,000 tons of military supplies. And, most importan t of all, badly needed reinforcements continued to arrive.15During these first six weeks of the operations in Korea the FarEast Air Forces played an important part in delaying the enemy.Lacking medium tan ks and artillery, the ground forces were particularly dependent upon the support of the air forces. In the initial

14 The beachheads at Salerno and Anzio were both much smaller, and the troopsthe re had to be supplied over the beaches.15 The American 2d Infantry Division (Major General Laurence B. Kaiser) arrived between 31 July and 15 August. The Am erican 1st Marine Brigade(Provisional) and the 5th Regimental Combat Team landed on 3 August.
http:///reader/full/facilities.14http:///reader/full/facilities.14http:///reader/full/arrive.15http:///reader/full/arrive.15http:///reader/full/facilities.14http:///reader/full/arrive.15


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12stages of the hostilities attempts had been made to provide closesupport for the ROK units. But since the la tte r's lack of air-groundcommunications rendered these efforts largely ineffective, attackshad to be confined almost entirely to ta rg ets of opportunity. Norwas air-ground coordination everything to be desired when American ground forces entered the fighting. Prio r to the war in Koreathe mission of the air units in Japan had been defensive in nature;and, therefore, neither equipment nor organization was on hand forair-ground coordination in mobile warfare. As a resu lt, there hadbeen a lack of joint training in this field. As the war progressed,however, a workable system was improvised with the personnel andequipment available; and by 1 August approximately 4,300 close-support missions had been flown. In addition, some 2,500 interdiction sorties had been flown and 60 strategic bombardment missions.The interdiction missions had been particularly effective, compellingvirtually all enemy traffic to move during the hours of darkness.Night sweeps along lines of communication had then been ins tituted .During this period the blockade established by the Navy deniedthe coastal waters to the enemy as a line of supply. Naval vesselsalso provided effective interdiction and ground-support fire, particularly on the east coast, where the slowing of the enemy advance toward Yongdok was due in large measure to naval gunfire support.Strikes by carrier-based planes supplemented the support by land-based aircraft and proved of great value to the men on the ground.In addition, the Navy was efficiently performing its traditional mission of providing logistical support for the ground and air forces.

Defense of the Pusan Perimeter (Map 4a ). T he period of fightingfrom 6 August until 15 September might well be considered a continuation of the delaying action, because it provided the necessarytime for General MacArthur to muster sufficient strength to launchhis offensive.While throughout this period the principal objective of the enemywas the destruction of the United Nations forces, the strategy employed followed two distinct pa ttern s. These, for purposes of. discussion, divide the operations into two more or less distinct phases.The first phase, lasting from about 6 August to 26 August, wasmarked by successive blows at individual points in determined attempts to break through the defense line; the second, between 27August and 15 September,16 was a period of heavy and almost simultaneous attacks around the entire perimeter.16 The dates given are approximate.


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13The first phase commenced with a United Nations spoiling a ttack.In order to throw off balance the expected enemy attack from Chinjutoward Pusan, General Walker organized Task Force Kean, which

consisted of the 25th Infantry Division (less the 27th RCT), the 1stMarine Provisional Brigade, and the 5th RCT. This force attackedon the morning of 7 August toward Chinju. The enemy attacked onthe same morning toward Masan, and the two forces met head-onearly in the day. Several days of heavy fighting followed; but by thenight of 11 August, Task Force Kean had occupied the high groundjus t east of Chinju. At th is time heavy enemy pressure on otherparts of the perimeter necessitated the transfer of some of the unitsof the task force; and, the immediate threat from Chinju being reduced, the remaining units withdrew step by step to their previousposition.Along the Naktong River front, north of th at river's junction withthe Nam, the North Koreans struck a series of severe blows, hopingto sever our main line of communication, which ran northwest fromPusan through Taegu. During the period 6-15 August the enemyestablished and reinforced several bridgeheads, the most threatening of which was jus t north of the Nam . The second half of Augustwitnessed desperate fighting along the river line, bu t all bridgeheadssouth of Waegwan that were of any consequence were finally reduced. The 24th Division was relieved by the 2d Division on 24August.

On the eastern flank the North Korean efforts to break throughthe perimeter came nearer success. Identified initially as guerrillas,a force of approximately division strength infiltrated this lightlyheld mountain area and by 12 August had fought its way into Po-hang. The ROK 3d Division, cut off south of Yongdok by this move,was evacuated by sea and landed below Pohang, where it re-established the right flank. Part of the Eighth Army reserve moved toYonil airfield, just south of Pohang, and succeeded in holding thatimportant fighter field. The remainder of the Eighth Army reservemoved north to Kyongju in order to be readily available in case of amajor breakthrough in this area. Fortunately, the enemy was notprepared to follow up his success. Pohang was retaken on 18 August, and ROK troopshad pushed well north of th at city by the 26th.

The last determined effort during th is period was made about mid-August when North Korean forces applied heavy but sporadic pressure down the Waegwan-Taegu road against the 1st Cavalry Division Little progress was made he re ; but an enemy attack from


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14Kunwi toward Taegu forced the ROK 1st Division to withdraw, exposing the valley road from Tabu to Taegu. Seeing this as the mostserious threat to Taegu, General Walker on 18 August committedthe 27th and 23d RCT's from army reserve to reinforce the ROK 1stDivision in th is area. Much bi tte r back-and-forth fighting took placealong the north-south valley road from Soi to Tabu. This stre tch ofroad, known to our troops as the "Bowling Alley", was the scene ofsome much publicized and excellent work by the famed 27th Infantry Regiment. Finally the enemy was halted.

An analysis of the North Korean attac ks during this period showsthat none was made in overwhelming strength and that the enemywas incapable of exploiting his successes. No single assault lastedmore than three days, as communications and supply could not further support it. The peak of every attack was reached on the second day; the power was gone on the th ird . As this phase ended, airand ground reconnaissance clearly indicated that the enemy wasmaking every effort to ga ther sufficient stren gth for further majoroperations.

During the second phase (27 August-15 September) of this periodheavy enemy assau lts took place around almost the entire perimeter(Map 4b ). Apparently Marshal Choi's stra tegy aimed at preventing General Walker from rushing his reserves from one threatenedpoint to another, as the latter had done during the earlier phase.The North Korean offensive began on 26 August with a strongsecondary attack in the Pohang area. Extensive enemy gains neces

sitated some reinforcement of the ROK I Corps. Then at 2400 on 31August, along the western perimeter of the beachhead, six enemydivisions plus several tank regiments launched a major effort aga instthe forty-five-mile front held by the 2d and 25th Divisions. In the25th Division sector the enemy was halted after much heavy fighting in which he gained considerable ground. By 5 September, however, the original front had been restored. On its wide front the 2dDivision had to cope with strong enemy forces that succeeded incrossing the Naktong a t seventeen different places and in advancingfour to six miles. But within a week the bridgeheads had been contained by the employment of local reserves and the 1st ProvisionalMarine Brigade. From 3 to 10 September, in some of the bitte res tfighting to date, the North Koreans registered gains of six to eightthousand yards against the 1st Cavalry Division and ROK tropps


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15in the Taegu area.17 The city of Taegu, however, remained in ourhands.Encouraged by the unexpected success of the 26 August attackin the Pohang area, Choi decided to renew it on 2 September. Athree-division atta ck pierced the front of th e ROK I Corps, capturedPohang on 6 September, and drove a deep salient to the TaeguKyongju-Pusan supply road. At th is point General Walker committed his reserve, the 24th Division, north of Kyongju. The division's counterattack, combined with a push by ROK troops againstthe western face of the salient, served to halt this southwesterly advance which had severed the supply road near Yongchon and whichsoon would have rendered the defenders' position in the Taegu areauntenable. However, up until the eve of the Eigh th A rmy's own offensive, units of the 24th Division were involved in bitter fightingto reduce the enemy's deep salient in the Kyongju area.Although the Eighth Army had survived its last'major crisis inthe beachhead area, hard fighting continued through mid-Septemberalong the en tire line of contact. For six weeks the defending forcehad used its interior lines and greater mobility to fend off a superiorforce that at no time was able to assemble sufficient logistical support to exploit a breakthrough.Of the 28,000 combat sorties flown by United Nations aircra ftsince the beginning of-the fighting in Korea, the greater part hadbeen in direct support of the ground forces. Yet the interdictionmissions flown had been so successful that the North Koreans hadbeen unable to undertake a major ground effort until the last day ofAugust. In addition, the few strategic ta rgets available had beenheavily damaged.The extent to which the North Korean Army was able to supplyits forces in the face of this heavy air effort is remarkable . Our airinterdiction could not halt rail movement entirely, as the trainsmoved only at night.18 Htfwever, by mid-August there was an acuteshortage of motor transportation for the final haul from railroad tobattle line. In the attempt to overcome this difficulty, animal-drawnvehicles and conscripted civilians (South Koreans) were pressedinto service. But the enemy supply situation grew steadily worse,17 The head quarters of the Am erican I Corps (Major G eneral Fr an k W. Milburn)arrived in Taegu on 13 Septem ber. The nex t day the I Corps assumedcontrol of the 1st Cavalry Division, the ROK 1st Division, and the UnitedKingdom 27th Infantry Brigad e. The last-named had arrived on 29 August and had been committed on the south flank of the 1st Cavalry Division on 5 September.8 The North Koreans made use of tunnels to conceal trains during the day.
http:///reader/full/night.18http:///reader/full/night.18http:///reader/full/night.18


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16resulting eventually in shortages of rations and clothing. Petroleum was also in short supply, although sufficient stocks were provided for armored vehicles. Am munition stocks were maintainedat fairly adequate levels.In contrast, the logistic requ irements of the United Nations forceswere met in spite of the growing demand created by the increase inpersonnel as well as the desperate natu re of the fighting. In August,alone, 595,000 measurement tons of supplies and equipment were unloaded at Pusan. In spite of the destruction or capture of nearly150 miles of rail lines by the enemy, the railroads carried 108,000tons of supplies to the combat areas. Units near the coast were supplied by LST's.THE UNITED NATIONS OFFENSIVE,16 SEPTEMBER-2 NOVEMBER 1950

The Amphibious Landing at Inchon (Map 5).The in i t ia t ive in; the Korean campaign changed hands abruptly on 15 September.$On_that date United Nations troops made a successful landing morethan 150 miles behind enemy lines in an operation similar to-GeneralMacArthur's many successful amphibious envelopments in World/War II.As early as 4 July, MacArthur had considered an amphibious landing at Inchon by the 1st Cavalry Division. Some amphibious tra ining was conducted; but when the critical situation around Pusan required immediate commitment of the division, the Inchon plans werepostponed. However, a joint planning staff, headed by Major General Edward M. Almond, Chief of Staff, Far East Command, continued detailed consideration of the problem of a strategic sea-borneenvelopment. This staff, working under pressure, produced its planin only a fraction of the time normally allotted. The basic problem,of course, was to determine where the landing should take place.Landings at Kunsan, Wonsan, Inchon, and elsewhere were considered. A landing at Inchon would involve practically every disadvantage known to amphibious specialists. There was an unusual tidalrange of over twenty-nine feet which would perm it use of the beachesfor only about three hours in twelve; at low tide there was a wideexpanse of mud flats in front of the difficult beaches; the channelwas narrow and the port facilities inadequate. But a landing atInchon had the prime strategic advantage of proximity to Seoul,whieh lay astride the major north-sou th supply arterie s. Other favorable considerations were' Seoul's psychological importance as Korrea's capital city and its value to the enemy as a supply base. Intel


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17' ligence estimates indicated that the area was comparatively lightlydefended.Despite the grave risk, General MacArthur, with the approval ofthe Joint Chiefs of Staff, decided that the amphibious assault wouldbe made at Inchon. He also insisted th a t the operation should takeplace on 15 September, th e earliest date on which th e tides would besuitable. The necessary directive was issued on 12 August, leavingonly a month for detailed plans and preparations that usually takefive or six months.The X Corps, designated to conduct the operation, was activatedon 16 August, with General Almond as its commander. The corpsconsisted of the 1st Marine Division, the 7th Infantry Division, andsupporting troops. The 7th Division (Major General David G. B arr ),tye last of the four divisions on occupation duty in Japan when theconflict began, was drawn from GHQ reserve. It contained 8,000ROK troops that had trained very briefly with the division in Japan.The 1st Marine Division (Major General Oliver P. Smith)'was assembled in Japan by moving the 1st Marine Brigade from Korea anduniting it with six Marine battalions drawn from the United Statesand the Mediterranean.The air preparation for this operation can be considered as havingbegun on 3 August with the initiation of the B-29 interdiction campaign in North Korea and the sh ifting in mid-August of a portion ofthe short-range air effort to similar atta cks in South Korea. Thisair offensive served a double purpose: restriction of the enemy's efforts against the Pusan perimeter and preparation for the comingoffensive by disrup ting his transporta tion facilities. The resu ltsLater became evident when the N orth Koreans were unable either toshift large units to the defense of Seoul or to regroup effectivelythe Eighth Army breakout from the Pusan perimeter,purposes of deception ROK marines made a minor landing atMokpo on the southwest coast and ex,ecuted feints at Kunsan on thewest coast and near Pohang and Yongdok on the east coast. Navalforces conducted a demonstration off Samchok.APrior to the landings naval aircraft from four carriers and firefrom four cruisers (two American and two British), six destroyers,and three rocket-firing landing craft pounded enemy defenses andIdeal transportation facilities for two days while the offshore areava.s being swept clear of mines. These naval forces, increased bythe arrival of another aircraft carrier, remained offshore and provide-1 air and gunfire support on call from the ground troops afterthe initial landings.


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18The plan for the first phase of the operation required the seizureof Wolmi, a tiny island which dominates Inchon harbor and whichis connected to the port of Inchon by a causeway (Map 6a). At dawn

on 15 September, about one hour before high tide , a reinforced b a t rtalion of the 1st Marine Division landed and captured Wolmi agains tlight resistance in less than th irty minutes.The plan for the second phase contemplated the seizure of theInchon peninsula. During the nex t high tide, at 1730 hours, otherelements of the 1st Marine Division assaulted the nine-foot sea wallin the port area . Nor th Korean garrison and security forces offeredlittle opposition; and by the afternoon of the next day, 16 Septem

ber, the marines were several miles east and northeast of Inchon.Kimpo airfield fell on the 17th, and on the following day it was serving as the terminus of an airlift operation that landed\400 tons ofcargo daily.The 7th Infantry Division came ashore on 18 September and assumed responsibility on the south flank. It fanned out quickly tothe south and east.The plan for the third phase contemplated the liberation of Seouland the denial to the enemy of the railroads and highways in thevicinity, vital link's in his lines of communication to the south. Marine troops crossed the Han River below Seoul on 19 September andadvanced rapidly on the city. Meanwhile, having secured Suwon,7th Division troops late on 26 September linked up with advance elejments of the 1st Cavalry Division, which was leading the breakoutfrom the Pusan beachhead. Other elements of the 7th Divisioncrossed the Han south of Seoul and entered the outskirts of the capital city. The columns advancing from north, south, and west encountered strong resistance; but Seoul fell on 26 September.Breakout from the Pusan Beachhead (Map 5).On the eve of theEighth Army's own offensive the enemy began another attack eastfrom Waegwan, and on the night of 15 September he was threatening the northern approach to Taegu. But despite this enemy thre at,and the rainy weather th a t almost eliminated air support, the Eigh th

Arm y began its general offensive on 16 September. :The landing at Inchon, deep in the enemy rear, had no immediateeffect on Marshal Choi's army in South Korea; and the Eighth Armyscored no appreciable gains Until 20 September. At this time it w asconfirmed th a t there was little depth to the enemy defenses. Whenthe "hard shell" was broken, there was nothing behind it to impedethe advance of the Eighth Army.


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19The drive of the 25th Division down the Masan-Chinju road, supported by gunfire from naval vessels off the south coast, experiencedheavy going for the first few days; but it soon gained momentum,

and on 26 September the division was several miles west of Chinju.The 2d Division,19 after several days of stubborn fighting, found asoft spot and pushed forward rapidly toward Kochang.On the no rth face of the perimeter, where ROK divisions attacked,the pattern of resistance was much the same. After resistingstrongly for four days, the enemy defense collapsed; and he withdrew in haste. The ROK troops followed as rapidly as their transport could carry them.The I Corps, made up of the 1st Cavalry Division, 24th Division,ROK 1st Division, and the United Kingdom 27th Brigade, made themost sweeping advance. The 24th Division, initially in corps reserve, was committed on the left of the 1st Cavalry Division. Afterbreaking the enemy defenses, both divisions established bridgeheadsacross the Naktong and drove rapidly northwest. In one day, 26September, leading elements of the 1st Cavalry Division sped morethan 100 miles behind enemy lines to form a juncture with troops of

the 7th Division in the vicinity of Osan.Although all or par t of eight North Korean divisions were isolatedin southwestern Korea, there was ample opportunity for individualsor small groups to escape to the nor th. Large numbers threw awaytheir arms and donned civilian clothing, which made it extremelydifficult to identify them. But despite this, during the period 15-30September United Nations forces took 23,600 prisoners.In southwestern Korea the 2d and 25th Divisions (IX Corps) continued to advance rapidly agains t the scattered but often formidablecounteraction of disorganized groups. Before the end of the monththe west-coast port of Kunsan was seized by the 25th Division. Destruction of by-passed enemy concentrations constituted a majorproblem. A difficult task assigned to the I Corps was to clear andmake secure the Taegu-Taejon main supply route.In the vast mountainous area east of the line Taegu-Seoul theROK divisions advanced rapidly against practically no opposition.On the east coast ROK troops reached the 38th parallel by 1 October.2019 The IX Corps (Major General John B. Coulter) became operational on 23 Sep

tember. Its major units were the 2d and 25th Divisions.20 As of this date approximately 21,000 ROK troops were attached to or inte

grated with American ground units. The ROK corps, frequently referredto in this narrative, were made up entirely of ROK units.


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21Division, the relentless drive up the Yesong River of the ROK 1stDivision, and the northwesterly sweep of the ROK 7th Division foretold the fall of the North Korean capital of Pyongyang, which wascompletely occupied on 21 October. On the previous day two battalions of the 187th Airborne Regimental Combat Team had beendropped by parachute a t Sukchon and Sunchon. W ith so little resistance actually being met a t Pyongyang, the effect of th is airborneoperation appears to have been slight. Of interes t, however, wasthe drop from C-119's of considerable heavy equipment, includingfour %-ton weapons carriers, twenty-eight 14-ton vehicles, twelve105-mm. how itzers, and four 90-mm. guns. While equipment hadbeen dropped in World W ar II , this was probably th e first operationaldrop of the heavier weapons and artillery pieces. With enemy resistance in a state of disintegration, troops advancing overland contacted the airborne forces on the 21st.

As the United Nations forces swept into the northern reaches ofKorea, the front broadened considerably. On 26 October the ROK6th Division reached Chosan, on the Manchurian border. At thesame time, to the east, the ROK Capital Division approached thearea south of the Choshin and Fusen reservoirs.Still operating as a separate command, the X Corps moved to theeast coast, where the 1st Marine Division disembarked at Wonsan on26 October21 and commenced clearing pockets of resistance whichhad been by-passed in the drive by ROK troops up the eas t coast.After their annihilating defeats, in which they had lost 135,000men as prisoners since mid-September, the North Korean forcesshowed little aggressiveness. By the end of the month the 24th Division had advanced to within a few miles of the temporary NorthKorean capital of Sinuiju (Map 8).THE CHINESE COMMUNIST INTERVENTION,3 NOVEMBER 1950-24 JANUARY 1951

Meanwhile resistance in front of ROK forces in the vicinity ofUnsan stiffened, and the presence of Chinese soldiers was verified.At first it was not clear whether they were members of North Ko21 The X Corps headquarters had arrived several days before and had assumedcontrol of the ROK I Corps. The original plan had contemplated an amphibious assault at Wonsan, but this was made unnecessary by the unexpectedly swift advance of the ROK I Corps up the east coast. I t was fortunate that such was the case, for the mines in the channel off Wonsanwere so numerous that six days were required to clear a channel for thetransports carrying the marines.


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22rean divisions or whether complete Chinese divisions had enteredthe conflict, but it was soon learned that the latter was the case.Strong attacks were launched against the ROK 6th and 8th Divisions, driving them back toward the Chongchon River. This reverseso threatened the troops near Sinuiju that General Walker decidedto pull them, together with the forces in the large salient in the center, back to the general line of the Chongchon River.Along the wide front of the X Corps the only enemy strength ofany significance was in the area of the Choshin and Fusen reservoirs .The 7th Division of that corps commenced debarking at Iwon on 29October. It moved rapidly toward Pungsan against.sporadic enemyopposition and by 21 November entered the Manchurian border townof Hyesanjin in sub-zero weather. W ithin a few days the 7th Division had assumed responsibility for the broad sector extendingsouthwest from Hyesanjin to the east side of the Choshin reservoir.In the meantime the 1st Marine Division, battling bitter weatherwhile reducing defended roadblocks, drove up both sides of the Choshin reservoir.The 3d Infantry Division (Major General Robert H. Soule) debarked a t Wonsan during .the first three weeks of November. Thedivision was made responsible for the security of the Wonsan areaand was given the mission of patrolling in the vast area to the leftof the 1st Marine Division. One of it s regim ents w as placed in XCorps rese rve.The lull which existed on the Eighth Army front after 6 November was utilized by General Walker to improve his logistical situationand to regroup his forces for furth er offensive operations. This regrouping included the movement of the IX Corps from South K orea.Briefly stated, the plan for the coming offensive contemplated a general assault northward by the Eighth Army combined with a XCorps attack against the enemy left flank and rear. The main enemysupply road, Kanggye-Huichon, would be the primary terrain objective of the X Corps. Originally the Eig hth Army assault wasscheduled for 14 November. The date, however, was changed to 24November to permit the arrival of the IX Corps, whose northwardmovement was delayed by heavy guerrilla activity in the Pyonggangarea th at threatened our main line of communication. ROK unitsassumed the anti-guerrilla and security mission in South Korea afterthe departure of the IX Corps.Because of the growing scarcity of close-support targets duringthe period 15 September to 24 November the emphasis of the aireffort gradually shifted to interdiction. In November alone these


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23interdiction attacks destroyed or damaged 650 trucks, 78 locomotives, over 1,800 railread cars, and more than 70 bridges. In evaluating the success of the enemy in building up his forces in the faceof this interdiction effort, it should be noted that his lines of communication from Manchuria were then quite short and that movements could be completed in a single nig ht. Also worth noting is theeffect of the restriction against flying over Manchuria, f This limitedthe directions of approach to the critical Yalu River bridges and prevented fighter escort planes from covering the north flank of bomberformations. Moreover, the enemy could concentrate his antiaircraftweapons to cover our limited approach zones; and his defending airsquadrons were free to move across the border to oppose our aircraftand then dart back to the safety of Manchuria.

Until 1 November our air forces had to contend with only the obsolescent propellor-driven aircraft of the inferior North Korean AirForce. Up to th at time only 8 United Nations a ircraf t had been lostin air action, as compared with enemy losses of 102 planes. On 1November, however, a new threat appeared when United Nationspilots were opposed for the first time by a number of Russian-builtMIG-15 jet aircraft which appeared briefly and then escaped to airfields in Manchuria.

Meanwhile reinforcements for the Eighth Army continued to arrive. Welcome additions were troops from the Philippines, Australia, Turkey, Thailand, and the Nethe rlands. Also arriving wereadvance parties from France and Canada, additional forces from theUnited Kingdom, and a hospital unit from Sweden. Personnelshortages in American units were made up by incorporating SouthKorean soldiers. A double purpose was thus served : bringing theUnited States units up to strength and providing training for theSouth Koreans which they could later pass on to their own units.Onjjjjjy^ovember the total of United Nations ground forces in Koreawas about 420,000, of whom 177,000 were Americans and approximately 200,000 were South Koreans.The logistical problems involved in the Inchon landing, in thetransfer of the X Corps from the west to the east coast, and in therapid overrunning of nearly the whole of the Korean peninsula areevident. Th at these problems were met and solved without a complete operational halt is a trib ute to those whose unspectacular efforts kept the military machine rolling. The major problem, ofcourse, was transportation in Korea itself. In a land of poor andscarce roads the railroads must always bear the b run t of the burden.These had been severely damaged; but by the end of October the


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24tremendous efforts of Army engineer groups, naval construction battalions, and Transportation Corps units had made it possible to placein operation 1,295 miles of rail lines, 245 locomotives, and 4,400,freigh t cars. Rail and truck hauls were reduced insofar as possibleby the opening of ports nearer the front, where supplies could belanded by DUKW's or light craft. Urgently needed supplies, including rations, gasoline, and ammunition, were moved forward by airtransport while surface lines of communication were being openedand expanded.

The Eighth Army offensive opened on 24' November. The attacking divisions advanced against light opposition until the night of25-26 November, at which time they were abruptly halted andthrown back by the large-scale (eighteen-division22) attack of theChinese Communist Forces, which had entered Korea from Manchuria. Similarly, the westerly advance of the X Corps, which began on27 November, was quickly stopped by an enemy force of nine divisions (Map 9).General MacArthur described the new situation as follows:The Eighth Army and affiliated United Nations units met powerful enemy resistance along the entire lineresistance which un

masked the fiction of "volunteer" 23 participation and disclosed themassive deployment of the Fourth Chinese Field Army, an important segment of the entire Chinese Communist military strength,in a formation of nine corps abreast in columns of divisions to anaggregate of twenty-seven divisions, with elements of the ThirdField Army discovered in initial deployment immediately to therear.

The main blow fell on the right wing of the Eighth Army andquickly severed the very tenuous contact existing between it andthe X Corps across the rugged ter rain in the center of the peninsula.Although the ensuing operations were concurrent, they will be described separately, as they took place on two distinct parts of thefront.Operations on the X Corps Front.Along the greatly extendedfront of the X Corps the heaviest enemy blow was directed at the

Choshin reservoir area, where the 1st Marine Division (less the 1stMarine Regiment) had just started its attack toward the west. AChinese Communist force struck both east and west of the Choshin22 A Chinese division is triangular in organization and varies in strength from

5,000 to 10,000.23 The Peiping Government had persistently maintained that all Chinese participants in the Korean war were volunteers.


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25reservoir on 28 November. The assault east of the reservoir quicklypierced the light line held by two battalions of the 7th Division(which had just relieved elements of the 1st Marine Division eastof the reservoir ), fanned out in their rear, and cut them off from thesouth. The most violent atta ck struck the marines on a broad frontwest of the reservoir and soon cut the main supply road in severalplaces. The marines and the two batta lions of the 7th Division wereswept into a pocket south of the reservoir, isolated from friendlyground forces and hammered from all sides.

The prodigious efforts of both land- ancf carrier-based aircraft insupport of the beleaguered troops reduced to some extent the greatodds against them. On numerous occasions the close air supportmade it impossible for the enemy to commit his forces in mass; hispiecemeal attacks were then turned back by the defenders. Nevertheless, the bitter cold weather combined with the fierce fighting totake a heavy toll.

' At length, late on 9 December, the 1st Battalion of the 1st MarineRegiment, which Had not been cut off, and a small task force fromthe 3d Infan try Division broke through to .join the isolated troops.After much severe fighting and many hardships the combined forcewithdrew to the port of Hungnam , where the m arines were loaded onwaiting transpo rts . Their embarkation was completed on 15 December.One of the most interesting features of the breakout from thepocket and the withdrawal was that, in spite of almost continuousaction with the enemy and poor road conditions, little heavy equipment was lost. For the crossing of one abyss C-119's dropped several spans of bridge equipment, which were assembled to provide atreadway bridge. W ithout it the column's vehicles, tanks, and artillery would have had to be abandoned.Meanwhile the strategic effect of the Choshin reservoir onslaught,rather than any direct attack, made it necessary for the X Corpstroops in northeastern Korea to retire.The left flank of the X Corps, originally along the upper reachesof the Taedong River, was entirely open except for such protectionas was provided by a few scattered patrols from the 3d Division.Chinese columns moving around the open flank advanced toward theport of Wonsan without opposition. In fact, th is movement proceeded undetected until it was observed by air reconnaissance in thevicinity of Yangdok. By 5 December small elements of the 3d Division and some ROK marines were isolated in Wonsan; bu t they weresoonevacuated by sea to Hungnam, where they reinforced the troops


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26of the 7th and 3d Divisions who were defending the port and thenearby Yonpo airfield.After the evacuation of the 1st Marine Division from Hungnamthe defensive perimeter was gradually contracted as the remainingunits embarked in succession. The troops of the 7th Division followed the marines, and then the regiments of the 3d Division wereembarked. The evacuation was completed on 24 December.The enemy attem pts to sweep the Hungnam defenders into the seahad been numerous and often in considerable s trength ; yet on no occasion was he able to mount a coordinated mass a ttack with adequateartille ry support. The defending forces, on the other hand, were ably supported by artillery that was effectively reinforced by navalgunfire. Carrier-based aircraft contributed greatly to the successful evacuation by flying thousands of close-support and interdiction missions. Naval vessels evacuated 203,000 persons (of whom105,000 were troop s) , 17,500 vehicles, and 350,000 measurement tonsof other cargo. In addition, air transpo rts took out 3,600 troops, 200vehicles, and 1,300 tons of cargo. Needless to say, th is operationcould have been carried out successfully only by the closely integrated efforts of the Army, Navy^ and Air Force.By 27 December the X Corps had completed the landing and assembling of its troops in the Pusan area. On the previous day thecorps had been placed under the Eighth Army.

Operations on the Eighth Army Front.Employing a force ofeighteen divisions, the Chinese Communists dealt the Eighth Armya stunning blow on 26 November] ' The main effort, directed at andaround the army's east flank, quickly smashed the divisions of theROK II Corps in that sector and exposed the right flank of the 2dDivision, in the IX Corps sector. Savage blows were struck at theremainder of the army front, but it was the primary threat of envelopment from the east that necessitated a withdrawal all alongthe line.The 1st Cavalry Division, the Turkish Brigade, and the BritishCommonwealth 27th Brigade were committed again st th e onrushingenemy on the Eighth Army's right flank. The combined efforts ofthese and othe r units made the withdrawal possible. Althoughlosses in men and equipment had been heavy,24 by 30 November theEighth Army was intact south of the Chongchon River.24 The 2d Division was particularly hard hit, suffering 4,163 casualties and theloss of much equipment. One art illery batta lion lost all bu t nine of itshowitzers; two other battalions either lost or were forced to destroy all oftheir pieces.


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27As the Eighth Army continued south across the Taedong River,the intensity of the fighting tapered off considerably. However, theright flank was still in the air; and a Chinese column succeeded in

cutting the Pyongyang-Wonsan lateral highway at Songchon whilethe Eig hth Army was still north of the road. This and other similarthrea ts were reduced, but the re was still no hope of stabilizing a linenorth of Pyongyang.The southward movement continued to positions below, Pyongyangand the Nan River. General Walker made every effort to contracthis broad front, refuse his right flank, and concentrate his delayingaction along the terra in corridor in the west. ,After 5 December the Chinese confined their offensive efforts topatrolling and probing action, though they continued to follow upthe withdraw ing troops. Even though enemy pressure had relaxedconsiderably, it was considered advisable for the Eighth Army tocontinue its retirem ent to a stronger defensive position. The XCorps had been cut away from the rest of the United N ations forces;and even if it could be evacuated and brought around by sea, it wasnot available now to reinforce General W alker's troops. Therefore,between 5 and 15 December the Eighth Army moved from south ofthe Nan River to a strong position which ran behind the lowerImjin in the west and thence eastw ard along the 38th parallel. TheROK units that had been delaying small bands of infiltrating NorthKoreans in the m ountains to the east were assigned zones of responsibility on the right of the new position. With minor exceptions,this front remained unchanged through 31 December.In the meantime remnants of North Korean units in South Koreahad infiltrated northward in sizable numbers to add seasoned veterans to divisions being reconstituted in North Korea and in Manchuria. After mid-December friendly patrols discovered an increasing number of North Korean units in the forward a reas. Concurrently there was a decided decrease in the numbers of Chinese inthe line. During the latte r half of December both air and groundreconnaissance observed an extensive build-up in rear areas of both

enemy troops, and equipments Then during the last few days of December major Chinese Communist forces moved into the line in thesector no rth of Seoul. Their patrols became more numerous andmore aggressive. Several attacks of regimental size aga inst theROK units on the right were apparently intended to draw attentionto th at sector. In short, at the year's end the re was every indicationof an impending large-scale enemy assault.


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28On 23 December, General Walker had been killed in a traffic accident no rth of Seoul. Lieutenant General Matthew B . Ridgway succeeded him as commander of the Eighth Arm y. General Ridgway's

combat forces now included contingents from nine nations otherthan the United States and the Republic of Korea.25It was estimated th a t enemy forces at the end of the year exceeded400,000, of which approximately 250,000 were Chinese Communists.Estimates of the total Chinese forces in Korea and in Manchuriawere about 740,000.There has been much controversy over the deployment of theUnited Nations forces in their advance from the 38th parallel to theManchurian border, based on the fact that the X Corps functionedas a separa te corps directly under General MacA rthur and th at a gapexisted between it and the Eigh th Army. The reasons for this canprobably be understood by noting the objective of the United Nations Forces at that time, the forces available for the attainment ofthat objective, and the terrain.The objective was to end the conflict at the earliest possible dateby capitalizing on the already sorry plight of the North KoreanArmy. All of North Korea was to be overrun and the remainingenemy forces destroyed.To accomplish th is objective, th e plan, as previously indicated, wasto strike northwest with the Eighth Army along the North Koreanmain* line of communicationtoward Sinuijuwhile th e X Corps,on the east flank, struck down the Yalu River. There was such ascarcity of roads that a larger enveloping force could hardly havebeen supported ; nor, in view of the lack of enemy streng th in easternKorea, does it appear that a larger force would have been requiredhad not the Chinese Communists intervened.

The reasons for the employment of the X Corps as a commandapart from the Eighth Army may be found in the terrain and in thesmall number of troops available to cover a front of 300 miles. Themaps give some idea of th e te rra in in the area between the two commands. The mountains are high, and the deep gorges between themare a bar to traffic even when the st reams are dry or frozen. Roadsare few, and those that do exist are not suited for heavy traffic.Transportation then becomes a problem for the pack mule and thehuman back ra ther tha n the self-propelled vehicle. Telephone wiresare difficult to lay and, with guerrillas on every hand, are doublyhard to maintain. Even radio is limited by such terra in, w ith a con25 Au stralia, Canada, Franc e, Greece, Ne therlands, Philippines, Thailand, Turkey,and the United Kingdom.
http:///reader/full/Korea.25http:///reader/full/Korea.25http:///reader/full/Korea.25


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29siderable reduction in range. In all, most observers have agreedtha t American forces have seldom fought in ter rain to which modernmeans of war are less adaptable.

There has been much discussion as to why the Chinese Communists were able io obtain such complete surprise for their offensivetha t began in late November. General MacArthur has given the following explanation :Political intelligence failed to penetrate the iron curtain and provided no substan tial information of intent. Field intelligence washandicapped by the severest limitations. Aerial reconnaissance beyond the border, which was our normal source of field intelligence,

was forbidden. Avenues of advance from border sanctu ary to battle area, only a night's march, provided maximum natural concealment. No intelligence service in the world could have surmountedsuch handicaps to determine to any substantial degree enemystreng th, movements, and intentions. This left ground reconnaissance in force as the proper, indeed the sole, expedient.The Second Invasion of South Korea (Map 10).Prior to Chris tmas the enemy began a series of probing and softening attacks

against the ROK units near the east coast and succeeded in penetrating to a distance of about eight miles through the sector of theROK 9th Division. This secondary attack was apparently intendedto draw attention to that part of the front.On the last day of December th e main attack came. Chinese Communist divisions poured across the 38th parallel on a broad front,from Kaesong east to the Pukhan River. Lacking the high" degreeof surprise enjoyed by the North Korean Army in June 1950, the

Chinese nevertheless moved quickly and with g rea t weight down th esame invasion pa ths. Attack ing in waves and seemingly indifferentto losses, by sheer weight of numbers they advanced through minefields, barbed wire, and automatic-weapon and artillery fire. On thefirst day the defenders were forced back ten to twelve miles.26On 2 January the X Corps assumed operational control of the. American 2d Division and the ROK 2d, 5th, and 8th Divisionsinthe central sector. The American 3d and 7th Divisions, recently

evacuated from the Hungnam beachhead, moved forward to bolsterthe I and X Corps, respectively.26 The serious situation on the left flank was caused by a regiment of the ROK1st Division (which was not properly dug in) allowing itself to be takencompletely by surp rise. Before the adjacent units knew what had happened, the Chinese in large numbers had penetrated this regiment's position.
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30Strong, unrem itting Chinese and North Korean onslaughts, whichwere particularly successful in the sector east of the Chungpyongreservoir, compelled a general United Nations withdraw al. On 4January, Seoul changed hands for the third time as the-1 and IXCorps moved south of the Han River and occupied defensive positions. However, the continued success of the North Korean andChinese Communist forces in the salient to the east soon renderedthis position untenable.By 7 January the United Nations forces had drawn back to andwere holding firm on a line that ran from Pyongtaek, on the west

coast, northeast toward Wonju.From the beginning of this second invasion the ROK units in theeastern sector experienced much difficulty in combatting thousands,of infiltrating North Korean soldiers, many of whom donned civilianclothes and mingled with the crowds of refugees moving south . Also,the refugees themselves were a serious problem. As many as twomillion South Korean civilians streamed south to escape the Communists, clogging roads and rail facilities and seriously hamperingmilitary movements in eith er direction. At Suwon a mob of nearly100,000 refugees blocked the railroad yards and prevented trainsfrom m oving. The problem was further complicated by the increasing activities of guerrilla bands behind the United Nations lines.After the first week in Jan uary activity in the western sector wasconfined to ligh t-patrol contact as the enemy's main effort shiftedto the center of the peninsula. A strong force of Chinese and North

Koreans drove down the Chunchon-W onju-Chechon corridor. Despite valiant defensive efforts, including numerous counterattacks,the enemy wrested from the 2d Division the importan t highway andrail center of Wonju. In the sector east of Wonju he was able topenetrate to within ten miles of Yongju. Part of the enemy forcesdrove east from this salient; part crossed the Chechon-Yongju roadand moved toward Mungyong and Chungju; and one North Koreandivision infiltrated across the Andong-Yongdok road to the mountainous ter rain between Andong and Yongchon. This last columnwas finally driven back by the 1st Marine Division. By 24 Januarythe invaders (except for those units which had infiltrated throughto the rugged terrain below Yongju) had been halted along the general line Pyongtaek-Wonju-Chechon-Samchok. This marked thehigh tide of the second invasion of South Korea.


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31THE FIRST UNITED NATIONS COUNTEROFFENSIVE,25 JA NU AR Y-2 1 APRIL 1951 (Map 11)

In mid-January th e tide of ba ttle changed once more. Enemy linesof communication, which had lengthened steadily since 26 November, now offered an unlimited num ber of rem unerative ta rgets for theair forces. This situation was in marked contrast to tha t which prevailed in late October and November, when enemy supply lines fromthe inviolate Manchurian border were so short that convoys couldtravel the distance in one night. Now, however, bombers blastedlucrative targets day and night.27 Naval aircraft and warships aggravated the foe's logistical problem by constantly pounding keycoastal communications centers.The Eighth Army inaugurated a series of limited-objective attacks that were preceded by reconnaissance operations of sufficientstrength to sweep back all enemy elements in front of his main lineof resis tance. The efforts of air and naval forces were closely integrated with those of the ground forces. The campaign objectiveswere several: to retain the initiative; to keep the enemy off balanceby unremitting pressure; to thwart his efforts to mass sufficientpower to undertake another general offensive; to inflict upon himthe heaviest possible losses in men and materiel. General Ridgwaystated his purpose in these words :We are not interested in real esta te. We are interested only ininflicting" maximum casualties on the enemy with minimum lossesto ourselves. To do this, we mu st wage a war of m aneuverslashing at the enemy when he withdraws and fighting delaying actionswhen he attacks.

Operation Thunderbolt.When patrols from the I and IX CorpsWere unable to locate enemy forces on their front, the I Corps, on 15January, sent forward a reinforced regiment to make a reconnaissance in force. These troops, in what was called Operation Wolfhound, advanced north to Suwon and discovered that the front opposite the I Corps was only lightly manned. A similar force, knownas Task Force Johnson, was dispatched by the IX Corps on 22 January. It brought back a similar report. With like reports from allalong the front, General Ridgway, on 25 January, launched Operation Thunderbolt, a limited-objective attack with the objective of regaining the terri tory south of the Han River. Supported by intensive interdiction attacks from the air, the I and IX Corps each ad27 The effectiveness of night close-support efforts, as well as night sweeps alonglines of communication, had been increased by the use of improved equipment and procedures, particularly by the use of high-candle-power flares.
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32vanced initially with one division in multiple columns. The advancewas deliberate, grea t care being exercised to insure that no by-passedenemy forces remained to ha rass rear elements. While unspectacular, the advance was steady . Additional units were soon comm itted,and the operation changed from a reconnaissance in force to a full-scale attack.Opposition remained light until 30 January, when considerable resistance was met on the front of both corps. Figh ting south ofSeoul was intense until 10 February, when resistance suddenly vanished before the 25th Division. The division made an 11,000-yardadvance on that date and secured the port of Inchon and Kimpo airfield, both of which had been demolished barely a month before bythe departing United Nations forces. However, the enemy retaineda bridgehead south of Seoul that was not eliminated until the nextmonth.

The Communist Counterattack.Meanwhile the X Corps and theROK I and III Corps launched a limited-objective attack similar toOperation Thunderbolt. Known as Operation Roundup, th is attack ,begun on 5 February , met little initial opposition. But by & February resistance had stiffened grea tly. Sightings of large enemy unitsfrom the air and increased vehicular movement in his rear areas indicated that a counterattack of major proportions could be expected.This blow fell on the night of 11-12 February, when the enemy attacked down the Hoengsong-Wonju corridor. Fig hting aroundWonju and Chipyong was heavy during the next four days, but thegarrisons of these towns fought valiantly and held on until reinforced. To the east the Communist drive carried to within sevenmiles of Chechon before it was halted.The enemy's purpose in this large counterattack was probablytwofold: (1) to relieve pressure on the Communist toehold south ofthe Han; and (2) to penetrate General Ridgway's lines, divide hisforces, and sever his vital lines of supply. But neither purpose wasachieved. The United Nations troops and commanders had learnedto "roll with the punch", inflicting the maximum punishment asthey drew back. Heavy casualties and the pause necessary for th eChinese to reorganize and replenish supplies brought the counterattack to a standstill, and by 19 February the initiative had againpassed to our hands.

On 21 February, Operation Killer was launched with the objectiveof wiping out the salient produced by the Communist counterattack.By 25 February the salient had been eliminated, and the Communist


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33forces were falling back under the pressure of our ground and airattacks.

Operation Ripper.During the last two weeks in February thewestern sector of the front had been relatively quiet, with the UnitedNations forces holding a line just south of and overlooking the HanRiver. There was no indication th a t e ither Seoul or the line southof the Han was heavily defended. However, to avoid a possible costlyfrontal assault on the city, it was decided to by-pass it in the nextoperation. This attack, known as Operation Ripper, began on 7March. The purpose, like that of the preceding attacks, was to inflict the maximum casualties and at the same time to outflank Seouland thus force its abandonm ent by the enemy. One of the primaryterrain objectives was the town of Chunchon, where the enemy wasbelieved to be concentrating his troops and supplies.

In the zones of the IX and X Corps, where the terrain was mostdifficult, the advance progressed slowly against strong resistance.Tank operations and the forward movement of supplies were particularly affected by th e combination of precipitous mountains, deep valleys, rivers, and rice paddies. Nonetheless, Hongchon was taken bythe middle of the month; and Chunchon was captured on the 22d.

Meanwhile, on the first day of the offensive, the 25th Division,which had heen moved to the east flank of the I Corps sector, crossedthe Han River fifteen miles east of Seoul, at the confluence of theHan and Pukhan Rivers. The enemy counterattacked th is bridgehead, but after three days of hard fighting he retired in disorder.The division's advance up the Pukhan Valley caused the Communists to evacuate Seoul on the night of 14-15 March, patrols of theROK 1st Division entering before daylight. This was the fourthtime that the city had changed hands.Resistance along the entire front quickly dwindled, and advancingunits began losing contact with the enemy. In an effort to block hiswithdrawal route, from Seoul to Kaesong, the second and largestairborne operation of the conflict was launched on 23 March. At0900 on that date the 187th Regimental Combat Team and two companies of Rangers were dropped in the vicinity of Munsan, togetherwith such heavy equipment as 14-ton trucks, weapons carriers, andhowitzers. Resistance was slight, and in a m atter of hours an armored column had made contact with the a irborne troops. While ithad been hoped th a t many of the enemy would be trapped, the actualnumber was negligible. They had retired too rapidly .


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34 Meanwhile the ROK I and III Corps advanced in their zones, capturing Yangyang, north of the 38th parallel, on 27 March. By theend of the month the United Nations front ran generally from Mun

san east to Chunchon and thence to Yangyang.The Advance Beyond the 38th Para llel.Although Operation Ripper had completed the liberation of most of South Korea, the enemy'sobvious build-up for still another counteroffensive made it imperative tha t he be kept off balance. To this end it was decided to establish a strong defensive line from which punishing sorties could bemade. The Eighth Army was therefore ordered to advance to the

commanding te rra in nor th of the parallel. This would establish aline, about 115 miles long, extending from the tidal land in the westthrough the twelve-mile expanse of the Hwachon reservoir andthence to the east coast through the almost impassible terrain eastof the reservoir. The grea t na tura l stre ng th of the line would permit a reduction of troops in forward positions and therefore an increase in the depth of the defense.The army continued its slow, steady advance, unspectacular but

with the maximum punishment being inflicted on the enemy. Thesouth bank of Hwachon reservoir was reached on 3 April. The enemy opened the g ates of the dam in an attem pt to slow the advance;but the delay was slight, and on the 18th the dam and the town ofHwachon were taken. The units on the right and left reached thenew line about the same time.Meanwhile a limited offensive known as Operation Dauntless waslaunched on 11 April in the zone ju st w est of the reservoir. The ob

jective was the disruption of enemy build-up in the ChorwonKumhwa-Pyonggang area, commonly known as the "Iron Triangle".That the enemy fought tenaciously to retain this area is easy to understand . For months it had been an assembly and storage area ;and, in addition, it was an all-important link in his communicationssystem . Once the triangle was lost, the Communists would no longerbe able to shift troops and supplies from north to south or acrossthe front; without it their ability to launch another general offensive would be seriously limited.As the I Corps slowly advanced toward this area, in almost handto-hand combat, the enemy reaction became more violent; and allalong the front it became increasingly apparent that a new Communist counteroffensive was soon to be launched.

On 11 April, General MacArthur was relieved of his command bythe President, General Ridgway stepping up to take his place. Lieu


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35 tenant General James A. Van Fleet was sent from the United Statesto take command of the Eighth Army.While the critical operations of the period from November throughMarch were being fought on the ground, air and naval forces didmuch to support our successful withdrawal and subsequent counteroffensive. That the winter drive of the Communists was not moresuccessful m ay well be due to the close support and interdiction missions flown by the Air Force and by the air arm s of the Navy andMarine Corps. Units tha t were cut off were supplied by air, as wellas others fighting in terrain so difficult that normal means of supplycould not be used. The importance of evacuation by air and waterhas already been indicated. Nor were the naval surface' elementslacking in means of assistance to the ground forces. Enemy supplyroutes near the coast were torn by naval gunfire; amphibious demonstrations, such as the one at Kansong on 31 January, kept himoff balance.

At the end of the period we were still supreme, in the air, bu t therewere signs that the Communists intended to challenge that supremacy. The number of MIG-15's th at opposed our F-84's and F-86's increased steadily. At 'the end of April it was estimated th at th e enemy had a total of 860 combat aircraft, including 260 jet fighters.THE CHINESE COMMUNIST FORCES SPRING OFFENSIVE,22 APRIL-8 JULY 1951At the opening of the first phase of the Communist spring offensive the enemy had a decided numerical superiority in ground troops.Deployed in depth, an estimated fifty to fifty-eigh t divisions (including four N orth Korean divisions) were in the combat zone. An es'timated seventy divisions, with an aggregate strength of about700,000 men, were south of the Yalu River. An additional half million men were believed to be in training in Manchuria.The United Nations ground strength, including support and supply contingents, totalled 417,000 men. Naval combat vessels in support included five aircraft carriers, one battleship, seven cruisers,and proportionate num bers of destroyers and lesser craft. Eighteengroups of the Far East Air Forces were committed to the Koreanconflict. These included two light bomber groups, th ree medium(B.-29) groups, one tactical reconnaissance group, seven fightergroups, and five troop carrie r groups. Of these only three fightergroups could be based in Korea. The remainder operated from basesin Japan and in Okinawa.


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36The First Impulse of the Offensive (Map 12). The offensiveopened at 2000 hours on 22 April with a heavy artillery concentration against the ROK 6th Division of the IX Corps, followed by in

fan try assau lts. Other attacks began about the same time. In thewest, Chinese columns crossed the Imjin River and moved towardSeoul; in the vicinity of Inje, North Korean troops attacked the ROKunits holding the eas tern portion of the United Nations line. Theinitial Communist objective was apparently the envelopment of Seouland the cutting of our principal transpeninsular highway, runningfrom Seoul to Kansong.The ROK 6th Division withdrew in an orderly manner until successive attacks drove a wedge between the two front-line regimentsand struck the reserve regim ent. W ithin twenty-four hours this division was over twelve miles south of its original position, where itwas attem pting to reorganize. The reorganization had not been completed when fur the r w ithdraw al became necessary. The division hadbeen reduced in strength from 8,000 to 2,500.The prec ipitate w ithdraw al of-the ROK division left a gap betweenthe 24th Division of the I Corps and the 1st Marine Division of theIX Corps. Enemy troops, including Mongolian horse cavalry, pouredthrough and tried to exploit the pene tration by striking a t the flanksand rear of the two divisions, which countered by refusing their exposed flanks. Giving ground gradually and fighting as they withdrew, the Am ericans limited the rollb

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