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."
Pacific War
In the early hours of 7 December (Hawaiian time), Japan launched a major surprise carrier-based air strike on Pearl Harbor without explicit warning, which crippled the US Pacific Fleet, leaving eight American battleships out of action, 188 American aircraft destroyed, and 2,403 Americans dead. At the time of the attack, the US was not officially at war anywhere in the world as the Japanese embassy failed to decipher and deliver the Japanese ultimatum to the American government before noon December 7 (Washington time), which means that the people killed or property destroyed at Pearl Harbor by the Japanese attack had a non-combatant status. The Japanese had gambled that the United States, when faced with such a sudden and massive blow, would agree to a negotiated settlement and allow Japan free rein in Asia. This gamble did not pay off. American losses were less serious than initially thought: the American aircraft carriers, which would prove to be more important than battleships, were at sea, and vital naval infrastructure (fuel oil tanks, shipyard facilities, and a power station), submarine base, and signals intelligence units were unscathed. Japan's fallback strategy, relying on a war of attrition to make the US come to terms, was beyond the IJN's capabilities.