Mezue ahịrịokwu na-esonụ: N'okpuru ọchịchị President John F. Kennedy, ọnụ ọgụgụ ndị agha US nọ na Vietnam mụbara n'okpuru usoro ihe omume Military Assistance Advisory Group site n'ihe na-erughị otu puku na 1959 ruo 16,000 na 1963. Onyeisiala South Vietnam bụ Ngo Dinh Diem ji aka ike
mmegbu e megidere ndị mọnk Buddha n'afọ 1963 mere ka ndị US kwado mwakpo agha na-egbu egbu megide Diem. Agha ahụ gbagara n'ihu n'afọ 1964 mgbe esemokwu Gulf of Tonkin gasịrị, nke a na-ekwu na otu onye agha US na-agbagha na ụgbọ agha agha ngwa ngwa nke North Vietnam. Mkpebi nke Ọwara Oké Osimiri Tonkin nyere Onye isi ala Lyndon B. Johnson ikike sara mbara iji mụbaa ọnụnọ ndị agha US, na-etinye ndị agha agha n'ala maka oge mbụ ma na-amụba ọnụ ọgụgụ ndị agha na 184,000. Onye ndu Soviet bụ Leonid Brezhnev zaghachiri site n'ịgbanwe usoro ndọrọ ndọrọ ọchịchị nke Khrushchev nke iwepụ na ịbawanye enyemaka nye ndị North Vietnamese, na-enwe olileanya ịrata North site na ọnọdụ ya na-akwado China. Otú ọ dị, USSR kpaliri ọgba aghara nke agha ahụ, na-enye enyemaka ndị agha zuru ezu iji jikọta ndị agha America. Site n'oge a, ndị agha ndị mmadụ nke Vietnam (PAVN), nke a makwaara dị ka ndị agha North Vietnamese (NVA) na-alụ agha ndị ọzọ na ndị agha US na South Vietnamese.