How Vietnam emerged as a unified nation?

In March 1945 Japan occupied Indo-China from the French. Incidentally, one of the constituents of indo-China is Vietnam.

The Vietnamese national movement was fought against the Japanese occupation during the Second World War.

At the end of the Second World War the Provisional Government of the Democratic Republic of Vietnam was proclaimed. Soon after, France tried to re-establish control over Vietnam. This was followed by the French colonial war in Vietnam that ended in 1954.

Vietnam became a center of the Cold War when a new phase of the Vietnam War started. The war against the US ended in 1975.

Saigon, the capital of South Vietnam, was liberated on 30 April 1975 and the very next year Vietnam emerged as an independent and unified nation.