Whereas the Vietnam war was fought in the Republic of Vietnam from 1955 to 1975 and involved regular forces from the Democratic Republic of Vietnam and Viet Cong guerrilla forces in armed conflict with the Armed Forces of the United States, the Armed Forces of allies of the United States, and the Armed Forces of the Republic of Vietnam; Whereas the Armed Forces of the United States became involved in Vietnam because the United States Government wanted to provide direct support by the Armed Forces to the Government of the Republic of Vietnam to defend against the growing threat of communism from the Democratic Republic of Vietnam; Whereas members of the Armed Forces of the United States began serving in an advisory role to the Government of the Republic of Vietnam in 1955; Whereas, as a result of the incidents in the Gulf of Tonkin on August 2 and 4, 1964, Congress approved the Gulf of Tonkin Resolution ( Public Law 88–408 ) by an overwhelming majority on August 7, 1964, which provided to the President of the United States the authority to use armed force to assist the Republic of Vietnam in the defense of its freedom against the Democratic Republic of Vietnam; Whereas, in 1965, ground combat units of the Armed Forces of the United States arrived in the Republic of Vietnam to join approximately 23,000 personnel of the Armed Forces who were already present there; Whereas, by September 1965, between 150,000 and 190,000 troops of the Armed Forces of the United States were in Vietnam, and by 1969, the number of such troops reached a peak of approximately 549,500, including members of the Armed Forces who were supporting the combat operations from Thailand, Cambodia, Laos, and aboard Navy vessels; Whereas, on January 27, 1973, the Agreement on Ending the War and Restoring Peace in Viet-Nam (commonly known as the Paris Peace Accords ) was signed, which required the release of all prisoners-of-war of the United States held in North Vietnam and the withdrawal of all Armed Forces of the United States from South Vietnam