Coming of World War II

Prof JensenMarch 2010

Battle of Britain: 1940

Messerschmitt Bf109 E version flew in 1939 with a 920hp Daimler-Benz DB601Aa engine. Maximum speed = 347mph, height =34,450 ft. range = 410 miles. (by 1942: 1500 hp and 428 mph). 20mm cannon in the propeller hub and two 7.9mm machine guns; 35,000 built

Secret weapon: radar

Road to Pearl Harbor

• 1920-35: naval disarmament in Pacific• 1930-45: J Army crushes democracy • 1931 Manchuria: seized by J Army– China: weak; war w Japan '37-45

• US: strongly favors China, anti-Japan– No neutrality– Arm China; send air force

Japan Conquest of China

1940-41

• Axis (1940); Tokyo close ally of Berlin? Not.– J focus on China, not Pacific, not USSR– little or no coordination; no sharing technology

• 1941: FDR threatens Japan: no steel, no oil– demand withdraw from China & Vietnam– key goal: stop Japan from killing USSR

Japan’s choices, 1941

• China• USSR• Britain, Australia,

Netherlands• USA

Oil Crisis

Japanese Navy vs. US• superior: night-fighting, optics, torpedoes,

aggressiveness & imagination– Zero best plane of 1941-42 (fast, long-range)– no innovation in airplanes

• equal: (at start:) ships & planes, gunnery, seamanship, admirals

• inferior: radio; radar; anti-aircraft; defense, logistics; repair; training; medicine; use of subs; poor teamwork with J Army; intelligence (MAGIC = decode J Navy)

War Jitters

US Leadership• Roosevelt: Active Commander in Chief

– Congress: Zip – Public Opinion = controlled– Joint Staff (Leahy) for planning– FDR close to Churchill

• Combined Staff (with Brits)

• War Dept (Stimson & civilians)– Army: Marshall, MacArthur, Eisenhower– Air Force: Arnold

• Navy Dept (Forrestal as key)– ADM King– Nimitz, Halsey, Spruance