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What was Japan’s Southern Operation during World War II?

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Pearl Harbor attack A U.S. battleship sinking during the Pearl Harbor attack.

The Southern Operation was a major Japanese military campaign during World War II, designed to secure essential raw materials—specifically petroleum, tin, and rubber—by seizing Allied-held territories in Southeast Asia and the western Pacific.1

Executed alongside the surprise attack on Pearl Harbor, the operation aimed to make Japan economically self-sufficient and establish a fortified defensive perimeter. The strategy involved two primary military drives:12
* One force advanced from Formosa through the Philippines.12
* A second force moved from French Indochina and Hainan Island through Malaya.12

These drives were intended to converge on the Dutch East Indies, with the capture of Java serving as the culmination of a planned 150-day campaign. Additionally, the operation sought to secure Hong Kong, Burma, and various island groups, including Wake Island, Guam, and the Gilbert Islands, to serve as outer bastions for the Japanese empire.12