1. Economic Rivalry: Japan's expanding economy relied on natural resources, particularly oil, that were largely controlled by Western powers, including the United States. The US imposed restrictions and embargoes on the supply of these resources to Japan, straining economic relations.
2. Territorial Disputes: Japan had expansionist ambitions in the Pacific region and sought to acquire territories for expansion. The US controlled various islands and territories in the Pacific, such as the Philippines, which obstructed Japan's plans for regional dominance.
3. Naval Competition: Japan's military, particularly the Imperial Japanese Navy, saw the US as a potential threat to its dominance in the Pacific. Japan sought to neutralize the US Navy's influence in the region, which resulted in a naval arms race between the two countries.
4. Ideological Differences: Japan's militaristic and expansionist ideology, known as "Greater East Asia Co-Prosperity Sphere," clashed with the US's promotion of democracy and anti-colonialism. Japan viewed the US as a barrier to its perceived right to dominate Asia.
5. US Support for China: Japan was at war with China since 1937. The US provided financial, military, and diplomatic support to China during this conflict. This support strengthened China's resistance and angered Japan, as it saw the US as interfering in its regional ambitions.
6. US Economic Sanctions: In response to Japan's aggression in China and its refusal to withdraw, the US imposed economic sanctions on Japan in 1940. These sanctions severely restricted Japan's access to critical resources, including oil, which was essential for its military and industrial operations.
These factors combined to create tensions and hostilities between the US and Japan, eventually leading to the Japanese attack on Pearl Harbor and the outbreak of war between the two countries.