Japan's surprise attack on Pearl Harbor marked a foolish decision. This decision was made by Japan's political and military leaders in late November 1941 with the aim of eliminating the main American threat in the Pacific Ocean and forcing the United States to accept Japan's new order, or at least remain neutral for a while, while Japan was advancing southward into Southeast Asia. This decision was based on Japan's erroneous judgments and expectations, including:
underestimating the strength and will of the United States. Japan believes that although the United States is economically and militarily strong, it lacks the preparation and determination for war, especially under the pressure of the European theater, and the United States is unwilling to go to war with Japan for the interests of the Pacific. Japan also believed that American public opinion was isolationist, did not support Roosevelt's foreign policy, and that America's multiculturalism and democracy would weaken its war effectiveness and unity. Japan has ignored the strong industrial and scientific and technological capabilities of the United States, as well as the national and moral cohesion of the United States, as well as the historical and traditional anti-aggression and anti-fascist stance of the United States.
Overestimating Japan's strengths and opportunities. Japan considers its geographical and military superiority in the Pacific to be unmatched, its navy and air force are the most advanced and elite in the world, its soldiers and commanders are the bravest and smartest, and its nation and morality are the noblest and most just. Japan also believes that its allies and forces in the Pacific are sufficient, that its allies in Germany and Italy will contain American power in Europe, that Japan's occupation of China and Southeast Asia will provide Japan's resources and markets, and that Japan's Asian neighbors will support Japan's idea of an Asian co-prosperity sphere. Japan ignored Japan's economic and material difficulties and inadequacies, as well as the number and strength of Japan's enemies and resistance.
The value and impact of Pearl Harbor were incorrectly estimated. Japan believes that Pearl Harbor is the most important US naval base in the Pacific, and if it can successfully destroy US warships and planes, it will be able to weaken US naval and air forces, delay US counterattacks, and win time and space for Japan's southward advance. Japan also believed that the attack on Pearl Harbor would undermine American morale and confidence, forcing the United States to negotiate and compromise with Japan, or at least remain neutral for a while. Japan ignored other important facilities and targets at Pearl Harbor, such as oil depots, dockyards, radar stations, etc., as well as American aircraft carriers and submarines, which were key factors in the U.S. war in the Pacific. Japan also ignored the political and psychological implications of Pearl Harbor, such as stirring up American anger and hatred, uniting American public opinion and **, joining the Allied war, and defeating Japan at all costs.