Japanese military expansion in Indochina began prior to the general assault on Southeast Asia and the Pacific in December 1941, and Vietnam served as a staging ground and supply base for troops advancing into other parts of the region. Until March 1945, the Japanese allowed the French administration to continue handling the affairs of the colony. This arrangement benefited the Japanese, who did not have to create a civil administration, but it complicated the situation of non-communist Vietnamese nationalists, who had looked to Japan to help them win independence from the French.