WWII: value of U.S. Lend-Lease military aid 1941-1949, by receiving country

Through the Lend-Lease Act, the United States provided over 50 billion U.S. dollars worth of aid to its allies. Roughly half of this was provided by the Department of War, with the United Kingdom, its colonies and dominions receiving almost 60 percent of War Department aid, such as aircraft, military vehicles, ammunition, and non-combat equipment. Most of the War Department's aid was sent as a direct shipment to the receiving country, with the recipient taking most of the responsibility for arranging transport.

Protecting supply lines

Throughout the war, supply lines from the U.S. to its allies often became primary targets for the Axis powers' navies. Routes from the U.S. to the United Kingdom were under near-constant threat from German submarines during the Battle of the Atlantic, while the Japanese push into the South Pacific was to cut off routes from the U.S. to Australia - ultimately leading to the major battles of the Coral Sea and Midway. Additionally, the protection of American supply lines to the Soviet Union led to the Allied invasion of Iran in 1941 (known as the Persian corridor). The Allies' ability to protect and reinforce their supply lines would eventually prove to be a decisive factor in the eventual Allied victory in 1945.

Alternative methods

The United States sent over 1.7 billion dollars worth of aid to China through various means - initially, aid was sent via direct shipments, before the U.S. had to deliver the aid itself when the Japanese took control of airfields in French Indochina (in Vietnam), cutting off Chinese lines. Similarly, as France fell under German control in 1940, a large share of responsibility for supplying French allies and resistance forces fell to the U.S. - over one million dollars worth of military equipment and supplies was sent (or smuggled) to French and Chinese forces through "Commanding General shipments". Other methods of aid distribution were known as in-theater transfers, where special or emergency circumstances required the U.S. to give its own materials to its allies. This included co-operative efforts with the British and French forces following the Invasion of Normandy, or the American volunteer pilots, known as the Flying Tigers, who supported the defense of China.