Throughout the twentieth century the Japanese, seeking access to resources lacking on the home islands, had energetically expanded their control of territory on the Asian mainland (northern China and Manchuria) and Pacific islands. When the war in Europe began in 1939, the Japanese Imperial General Staff quickly realized that Britain, France, and the Netherlands would not be in a position to defend their resource-rich holdings in the Pacific. Opposition to its expansionist plans could come only from the United States, which, though still officially neutral, had actively opposed Japanese aggression in Asia with diplomatic and fiscal devices. Given U.S. industrial superiority, the Japanese planned for a quick and decisive victory.

Japan began the war with victories that were dramatically quick and overwhelming, including the "surprise attack" (a favorite tactic of the Japanese armed forces) on Pearl Harbor. The early victories over the U.S., British, Dutch, Australian, and New Zealand forces could not be sustained in the face of the logistical and industrial strengths of the Allies, primarily those of the United States. By summer 1943, Japan was in retreat on all fronts.

This was an era of "total war," that is fighting was intense and sometimes brutal not only on the front but also in the cities; to wage total war required the ultimate commitment of all resources, human and material. Because it was a total war the Allies demanded nothing less than unconditional surrender. This module is divided into three sections. The first traces Japanese expansion from the end of World War I to its greatest expansion in the spring of 1942. The second section focuses on the turning point of the war, the critical battles of Midway and Guadalcanal (summer and fall of 1942). The third section documents the allied counter-offensive to the end of the war in the Pacific. The module concludes with an overview of the battle of Midway.