Rubuta ci gaba don wannan sakin layi - A karkashin Shugaba John F. Kennedy, yawan sojojin Amurka a Vietnam ya karu a karkashin shirin Kungiyar Ba da Shawarar Taimakon Soja daga kasa da dubu a 1959 zuwa 16,000 a 1963. Shugaba Ngo Dinh Diem na Kudancin Vietnam ya yi amfani da karfi a kan Buddha
a shekarar 1963 ya jagoranci Amurka ta amince da wani mummunan juyin mulki na soja a kan Diem. Yaƙin ya ƙara ƙaruwa a cikin 1964 bayan rikicin rikice-rikicen Gulf of Tonkin, wanda aka yi zargin cewa wani jirgin ruwa na Amurka ya yi karo da jirgin ruwa mai saurin kai hari na Arewacin Vietnam. Kudurin Gulf of Tonkin ya ba Shugaba Lyndon B. Johnson cikakken izini don kara yawan sojojin Amurka, da tura rundunonin yaki na kasa a karon farko da kara yawan dakarun zuwa 184,000. Shugaban Soviet Leonid Brezhnev ya mayar da martani ta hanyar sauya manufofin Khrushchev na rabuwa da kara taimakon ga Arewacin Vietnam, da fatan ya jawo Arewa daga matsayinta na China. Duk da haka, USSR ta hana ci gaba da yakin, duk da haka, ta samar da taimakon soja kawai don ɗaure sojojin Amurka. Daga wannan lokacin, Sojojin Jama'ar Vietnam (PAVN), wanda aka fi sani da Sojojin Arewacin Vietnamese (NVA) sun shiga cikin yaƙe-yaƙe na yau da kullun tare da sojojin Amurka da Kudancin Vietnam.