The communists attacked South Vietnamese targets during the 1968 Tết Offensive . Although the campaign failed militarily , it shocked the American establishment , and turned US public opinion against the war . During the offensive , communist troops massacred over 3,000 civilians at Huế . Facing an increasing casualty count , rising domestic opposition to the war , and growing international condemnation , the US began withdrawing from ground combat roles in the early 1970s . This process also entailed an unsuccessful effort to strengthen and stabilise South Vietnam . Following the Paris Peace Accords of 27 January 1973 , all American combat troops were withdrawn by 29 March 1973 . In December 1974 , North Vietnam captured the province of Phước Long and started a full-scale offensive , culminating in the fall of Saigon on 30 April 1975 . South Vietnam was briefly ruled by a provisional government for almost eight years while under military occupation by North Vietnam
massacred over 3,000 civilians
Massacre at Huế
Vietnam