Early Vietnam involved France rejecting Vietnam's post-WWII independence and an 8-year struggle ensuing. The US initially sided with France but grew concerned about communist expansion. This led the US to financially support France in Vietnam as part of containing communism. By 1954, Vietnam was partitioned, but the US feared communist victory in unification elections and backed South Vietnam's leader Diem instead. This divided Vietnam and marked the US replacement of France in fighting communism in Southeast Asia.