Why did U.S. commanders expect a Japanese attack in the Philippines or Southeast Asia instead of Hawaii?

U.S. commanders expected a Japanese attack in the Philippines or Southeast Asia rather than Hawaii because Japan’s strategic objectives were focused on securing vital raw materials—such as petroleum, tin, and rubber—located in European colonial territories like the Dutch East Indies and Malaya.12

Japanese military planning aimed to overwhelm Allied forces in the western Pacific to establish a defensive perimeter that would allow them to exploit these resources. Because the eastern Pacific was largely devoid of landmasses and bases, U.S. leadership did not anticipate that Japan would launch a strike as bold or distant as the one on Pearl Harbor. Furthermore, while U.S. commanders were warned of the possibility of war in late 1941, they focused their defensive preparations on sabotage and reconnaissance in areas closer to the expected theaters of conflict, failing to identify the Hawaiian Islands as a primary target for a major offensive.13