North Vietnam and South Vietnam. Also, to name just a few: the USA, China, Russia, South Korea, Australia, France, and England. A great many countries fought in the Vietnam War from 1945 to 1975.
Primary combatants were US & North Vietnam; especially the air war over the North.
The Soviet Union (USSR) supplied North Vietnam, and the US fought for South Vietnam.
The fight against the spread of Communism.
The countries that were actually "physically" involved, and were bombed or had US aircraft crash into them, whether they were "officially" in the war or not, were: Lao's, Cambodia, North Vietnam and South Vietnam.
The two countries have borders with Vietnam, and were a way to move men and materiel from North Vietnam to South Vietnam avoiding the narrow coastal region.
Nobody knows. Too bad.
North Vietnam won them.
The United States did get involved in the Vietnam war because of communism in Vietnam.
Since it involved two or more nations, yes.
korea, united states, ussr, vietnam, and germany?
Vietnam was a French colony, called French Indochina. The French were involved in the beginning. When they 'left' the US got involved. There were some other countries with much less involvement as well, Australia also had a few soldiers there.
There were not only two countries.