When Japanese bombers appeared in the skies over Pearl Harbor on the morning of December 7, 1941, the U.S. military was completely unprepared for the devastating surprise attack, which dramatically altered the course of World War II, especially in the Pacific theater. But there were several key reasons for the bombing that, in hindsight, make it seem almost inevitable. Tensions Began During the Great Depression Before the Pearl Harbor attack, tensions between Japan and the United States had been mounting for the better part of a decade. The island nation of Japan, isolated from the rest of the world for...