Military history of the United States during World War II Military history of the United States during World War II The military history of the United States in World War II covers the war against Germany, Italy, and Japan, starting with the 7 December 1941 attack on Pearl Harbor. During the first two years of World War II, the United States had maintained formal neutrality as made official in the Quarantine Speech delivered by U.S. President Franklin D. Roosevelt in 1937, while supplying Britain, the Soviet Union, and China with war materiel through the Lend-Lease Act which was signed into law on 11 March 1941, as well as deploying the
Resistance during World War II occupied Poland during World War II, essentially a continuation of the Zamosc Uprising. During Operation Most III, in 1944, the Polish Home Army or Armia Krajowa provided the British with the parts of the V-2 rocket. Norwegian sabotages of the German nuclear program drew to a close after three years on 20 February 1944, with the saboteur bombing of the ferry SF Hydro. The ferry was to carry railway cars with heavy water drums from the Vemork hydroelectric plant, where they were produced, across Lake Tinn so they could be shipped to Germany. Its sinking effectively ended Nazi nuclear ambitions.