First Indochina War
The First Indochina War was a war in Indochina between the French who ruled it and the Vietminh who were communist rebels. Stalin sent tons of weapons to Mao, who gave them to the Vietminh and trained them in using these. In response, the United States sent the French artillery, tanks, and planes. At first the French won, but at Dien Bien Phu the Vietminh hacked a road to this fort and forced its surrender by firing Chinese artillery guns. The French left. North Vietnam became a communist tyranny, South Vietnam a free republic.
Not long after the French were expelled, the Vietnam War started.