Empire of Japan attack on Pearl Harbor Axis powers intern Japan Allies
A total of $50.1 billion (equivalent to $719 billion in 2021) worth of supplies was shipped in 1941–1945, or 17% of the total war expenditures of the U.S. On December 7, 1941, the Empire of Japan launched a surprise attack on Pearl Harbor, prompting the United States to militarily join the Allies against the Axis powers, and in the following year, to intern about 120000 Japanese and Japanese Americans.