On December 7, 1941 the Japanese Military dropped a series of bombs on the U.S. naval base at Pearl Harbor on the island of Oahu, Hawaii in a surprise attack which killed and injured a record number of Americans. Over 2335 servicemen and 86 civilians were killed. In total 1178 peopled were injured. The next day the U.S. would declare war on the Empire of Japan. This lead to the direct involvement of the United States into World War II. On that same day President Franklin Roosevelt issue Presidential Proclamation – No. 2525 which was part of the of Alien and Sedition Act giving the Executive the power to imprison or deport enemy aliens from enemy nations.
This act of war enflamed already existing tensions and fears between natural born Americans and the two generations of Japanese Americans presiding in what would later be deemed zone one. This would culminate in the isolation of those thought to be a threat to national security by direct executive order 9066 to be evacuated by military force to corresponding internment camps until the end of WWII. At the end of the war, by executive order, those Japanese Americans were allowed to leave.
Some of this panic was intensified by those who feared more attacks from Japan or worse an attack from within by Japanese Americans who were loyal to Japan. Historian Dr. Roger Daniels describes how one U.S. General John L. De Witt in particular was especially paranoid about a recurring attack. In his book, "The Decision to Relocate the Japanese Americans" he describes how primary documents of the General's chief subordinate Joseph W. Stilwell diary and transcripts from military phone conversations detail a false alarm which emanated from De Witts's office on the same day as the attack on Pearl Harbor regarding a Japanese air raid taking place in San Francisco. This was followed two days later by a similar alarm of a Japanese fleet 164 miles of the coast of San Francisco. Daniels goes on to describe how it was from the "amateurish, panic-ridden headquarters that the first military proposal for mass evacuation was developed." It was after another such false attack when General De Witt's staff became convinced twenty thousand Japanese in the San Francisco Bay Area were going to participate in an armed rebellion. It was from his headquarters that the recommendation for "large-scale internment” was passed on to Washington DC. On December 19, 1941 General De Witt officially recommended that action be initiated at the earliest practicable date to collect all alien subjects fourteen years of age and over, of enemy nations and remove them to the interior of the United States.” This plan never took place because of the protests that took place from the many immigrant communities. “The nonwhite Japanese, however, had fewer defenders.”