Question

What U.S. territory threatened Japan’s access to oil, simply by being dangerously close to Japan’s oil-shipping lanes in the Pacific?

Answer 1

After Hitler invaded Russia in June 1941, Japan moved into southern Indochina. FDR ordered all Japanese assets frozen. But FDR did not want to cut off oil. As he told his Cabinet on July 18, an embargo meant war, for that would force oil-starved Japan to seize the oil fields of the Dutch East Indies.