From Wikipedia

The 10,000 Day War
Episode One

 America In Vietnam

Events in Southeast Asia

Main articles: Mayagüez Incident, Socialist Republic of Vietnam, Democratic Kampuchea, Third Indochina War, Reeducation camp, and boat people

Phnom Penh, the capital of Cambodia, fell to the Khmer Rouge on 17 April 1975. Over the next four years, the Khmer Rouge would enact a genocidal policy that would kill over one-fifth of all Cambodians. After repeated border clashes in 1978, Vietnam invaded Democratic Kampuchea (Cambodia) and ousted the Khmer Rouge in the Cambodian–Vietnamese War. In response China invaded Vietnam in 1979. The two countries fought a brief border war, known as the Third Indochina War or the Sino-Vietnamese War.

The Pathet Lao overthrew the royalist government of Laos in December 1975. They established the Lao People's Democratic Republic.