Japanese-American Claims Act
The attack on Pearl Harbor was a surprise military strike by the Imperial Japanese Navy on the United States naval base at Pearl Harbor in Honolulu, Hawaii, on the morning of December 7, 1941. The attack sank four U.S. battleships, destroyed 188 U.S. aircraft, and killed 2,403 U.S. citizens within two hours, and led to the United States joining World War II. Once the United States entered the war and anti-Japanese sentiment began to circulate, Americans increasingly reacted with racism and hostility, viewing people of Japanese descent were treated as enemies regardless of whether they were U.S. citizens. The U.S. government expressed concerns about the loyalty of the Japanese people living in America and about Japanese spies sending information to Japan. "The U.S. Department of the Treasury froze the assets of all citizens and resident aliens who were born in Japan, and the Department of Justice arrested some 1,500 religious and community leaders as potentially dangerous enemy aliens. Because many of the largest populations of Japanese Americans were in close proximity to vital war assets along the Pacific coast. The result was President Franklin D. Roosevelt's Executive Order 9066."
Events leading to the attack on Pearl Harbor
Genda, who saw Hawaii as vital for American operations against Japan after war began, believed Japan must follow any attack on Pearl Harbor with an invasion of Hawaii or risk losing the war. He viewed Hawaii as a base to threaten the west coast of North America, and perhaps as a negotiating tool for ending the war. He believed, following a successful air attack, 10,000-15,000 men could capture Hawaii, and saw the operation as a precursor or alternative to a Japanese invasion of the Philippines. In September 1941, Commander Yasuji Watanabe of the Combined Fleet staff estimated two divisions (30,000 men) and 80 ships, in addition to the carrier strike force, could capture the islands. He identified two possible landing sites, near Haleiwa and Kaneohe Bay, and proposed both be used in an operation that would require up to four weeks with Japanese air superiority.