主题：【整理】《阿基米德大战》 -- 孟词宗

In the 1930s, Japan expanded slowly into China, which led to the Second Sino-Japanese War in 1937. In 1940, Japan invaded French Indochina in an effort to embargo all imports into China, including war supplies that were purchased from the US. That move prompted the US to embargo all oil exports, which led the Imperial Japanese Navy (IJN) to estimate it had less than two years of bunker oil remaining and to support the existing plans to seize oil resources in the Dutch East Indies.

Planning had been underway for some time on an attack on the "Southern Resource Area" to add it to the Greater East Asia Co-Prosperity Sphere Japan envisioned in the Pacific.

In 1938, the U.S. began to adopt a succession of increasingly-restrictive trade restrictions with Japan, including terminating its 1911 commercial treaty with Japan in 1939, which was further tightened by the Export Control Act of 1940. Those efforts failed to deter Japan from continuing its war in China or from signing the Tripartite Pact in 1940 with Nazi Germany and Fascist Italy, which officially formed the Axis Powers.