World War II

World War II. European Theatre. The United States entered World War II on December 7, 1941, as Japan attacked the Pacific Fleet at Pearl Harbor. Four days later, Adolf Hitler declared war on the United States, and the U.S. entered into a global conflict., In November 1942, President Roosevelt committed U.S. ground forces to a campaign in North Africa under the command of General Dwight Eisenhower. U.S. Army Air Forces provided extensive support to the allied ground campaign, and to the campaigns that followed in Sicily and Italy, gaining air superiority, attacking German defenses, and disrupting the transportation networks supporting Axis forces. These campaigns were important both in supporting the Allied ground operations, and in enabling U.S. air forces to develop the doctrine, tactics and procedures they would need in the intense battles against Germany's forces in northern Europe. , During the early war years, the U.S. deployed increasingly powerful bomber forces to Great Britain, building the capability to conduct attacks against Axis forces and infrastructure in occupied Europe. U.S. Army Air Forces aircrew flew B-17 and B-24 bombing campaigns against German submarine construction yards, aircraft factories, transportation networks, ball bearing, and oil plants. By early 1944, long-range escort fighters-primarily the P-51 and the P-47-had gained the range to escort bombers throughout Germany, protecting the bombers while overwhelming German fighter forces. As allied forces prepared to invade occupied Europe, U.S. air forces fought to isolate the battlefield and gain air superiority in support of the landing that would return Allied forces to mainland Europe. , Allied leaders defined air superiority as a prerequisite to the landing in Normandy. Allied air forces supported the landings by inserting 17,000 paratroopers via C-47 airdrop and combat gliders, spreading confusion through the German defenses. During the campaign to break out of the Normandy beachhead, Airmen innovated in the close air support role, using close communication and aggressive tactics to assist ground units. This allowed such units to move quickly, and played a key role in the Army's drive across France. Airmen clearly demonstrated their value in both strategic bombing and in cooperation with ground forces, contributing to Germany's collapse in May 1945.