Who were the main adversaries in the Vietnam War?

The main adversaries in the Vietnam War were the United States and North Vietnam. This conflict, which lasted from the late 1950s to 1975, primarily revolved around the United States' effort to prevent the spread of communism in Southeast Asia, which they feared would extend from North Vietnam to neighboring countries. North Vietnam, supported by communist allies, aimed to unify the country under a communist government and sought to eliminate the influence of the U.S. and its support for South Vietnam.

While South Vietnam was an ally of the United States and fought against the North, it was not an independent adversary but rather a battleground for the conflict between the U.S. and North Vietnam. The roles of the Soviet Union and the United Kingdom were not primary in this war; the Soviet Union provided some support to North Vietnam, but it was not an adversary in the direct sense of fighting in the war itself. Similarly, the United Kingdom had no active combat role opposing North Vietnam, rendering them irrelevant to the question of the main adversaries in the conflict.