Powers Collide

What were Japan’s motivations and objectives in entering World War II in the Pacific and its invasion of countries in Southeast Asia? The pivotal issues include:

  • Japan’s political and military strategy in Asia prior to the outbreak of the Pacific War (Greater East Asia Co-Prosperity Sphere and invasion of French Indochina and its “Southern Resource Area” policy).
  • Japan’s rationale for attacking Pearl Harbor and opening of the Pacific front of World War II.
  • Impact of Japanese victory over colonial powers in Southeast Asia.

Japan gained a foothold in Southeast Asia by advancing into French Indochina (in present-day Vietnam, Cambodia, and Laos) in September 1940. President Franklin Roosevelt, already alarmed by Japan’s violent attack on Nanjing, China, imposed an oil embargo and froze Japanese assets in the United States. European powers followed suit, halting Japan’s oil supply. Japan faced an immediate choice: withdraw from China or secure oil elsewhere.

Japan decided to bomb the US Pacific Fleet at Pearl Harbor on December 7, 1941, and simultaneously launch an invasion of the Philippines and other targets in Southeast Asia. With the United States distracted and its navy hobbled, Japan assaulted Allied forces throughout Southeast Asia, and by March of 1942 controlled most of the region — and the natural resources, such tin, rubber, and petroleum reserves, which Japan needed to fuel its global ambitions.

Japan touted its victory as a triumph for Asian autonomy, calling for a “Greater East Asia Co-Prosperity Sphere.” In various countries and communities, and among religious and ethnic groups, the Japanese occupation took divergent forms. Some groups were treated favorably, and others mercilessly. Likewise, some people resisted Japanese authority, and others collaborated.

The links below shed light on how people across Southeast Asia endured vastly disparate experiences until Japan’s defeat and withdrawal in 1945, and the powerful role their experiences played as the region rebuilt in the wake of war.

Fast Facts

Timelines

Maps

Learning Modules

Readings