It was officially fought between North Vietnam, supported by the Soviet Union, China, and other communist allies, and South Vietnam, supported by the United States and other anti-communist allies.
U.S. involvement escalated under President John F. Kennedy, from just under a thousand military advisors in 1959 to 23,000 in 1964.
[3][4] After the Gulf of Tonkin incident in August 1964, the U.S. Congress passed the Gulf of Tonkin Resolution and gave President Lyndon B. Johnson broad authority to increase the U.S. military presence in Vietnam.
Johnson ordered the deployment of combat units for the first time and increased troop levels,[3] reaching a peak of 543,000 in April 1969.
By partial comparison, as of June 2022[update], the U.S. Department of Defense shows 126 awarded to Navy recipients[8] and 370 to Marines Corps recipients,[9] for acts of valor during the Vietnam War.