In 1956, elections were scheduled to be held to unify the country, but they were never held due to the outbreak of the Vietnam War. The war escalated and became increasingly internationalized, with the United States providing significant support to the south and the Soviet Union and China providing support to the north.
The war ended with the signing of the Paris Peace Accords in 1973. The accords called for a ceasefire, the withdrawal of all foreign troops, and the eventual reunification of Vietnam. However, the south Vietnamese government refused to accept the terms of the accords, and the war continued.
In 1975, the communist forces finally launched an offensive and took control of South Vietnam. The country was officially reunited under communist rule in 1976, and the Socialist Republic of Vietnam was established.