At the outset of World War II, tensions between Japan and the United States had been steadily escalating due to a combination of geopolitical ambitions and economic factors. Japan sought to expand its influence in Asia and the Pacific, aiming to secure resources for its growing military and economy. This expansionist agenda clashed with U.S. interests in the region, particularly the desire to maintain stability and prevent Japanese domination.
The United States, at the start of the war, was officially neutral, adhering to a policy of isolationism that aimed to keep America out of foreign conflicts. However, the U.S. was already providing support to Allied nations through measures such as the Lend-Lease Act, which aided countries fighting against Axis powers. While America had significant reservations about Japan’s actions in China and its wider imperial ambitions, it initially chose not to intervene directly.
Things changed dramatically after the attack on Pearl Harbor on December 7, 1941. This surprise military strike by Japan targeted the U.S. Pacific Fleet and resulted in heavy losses for the U.S. Navy and significant damage to military infrastructure. In the wake of this event, the U.S. declared war on Japan, marking its full entry into World War II. The attack fundamentally altered American public opinion and military strategy, transforming the nation from a position of neutrality to active engagement in the global conflict.