Third and fourth terms of the presidency of Franklin D. Roosevelt
On the morning of December 7, 1941, the Japanese struck the U.S. naval base at Pearl Harbor with a surprise attack, knocking out the main American battleship fleet and killing 2,403 American servicemen and civilians. The great majority of scholars have rejected the conspiracy thesis that Roosevelt, or any other high government officials, knew in advance about the Japanese attack on Pearl Harbor. The Japanese had kept their secrets closely guarded, and while senior American officials were aware that war was imminent, they did not expect an attack on Pearl Harbor. Roosevelt had anticipated that the first attack would take place in the Dutch East Indies, Thailand, or the Philippines.
United States Pacific Fleet
In December 1941, the fleet consisted of nine battleships, three aircraft carriers, 12 heavy cruisers, eight light cruisers, 50 destroyers, 33 submarines, and 100 patrol bombers. This was approximately the fleet's strength at the time of the Japanese attack on Pearl Harbor. That day, the Japanese Combined Fleet carried out the attack on Pearl Harbor, drawing the United States into World War II in the Pacific. The Pacific Fleet's Battle Line took the brunt of the attack, with two battleships destroyed, two salvageable but requiring lengthy reconstruction, and four more lightly to moderately damaged, forcing the U.S. Navy to rely primarily on aircraft carriers and submarines for many months afterward.