A tsakiyar 1940, Nazi Jamus ta ci nasara da Jamhuriyyar Faransa ta Uku cikin sauri, kuma gwamnatin mulkin mallaka na Faransa Indochina (Vietnam, Laos da Cambodia ta yau) ta wuce zuwa Ƙasar Faransa (Vichy France).An ba da dama da yawa ga DaularJapan da ke kawance da Nazi, kamar amfani da tashoshin jiragen ruwa, filayen jiragen sama, da hanyoyin jirgin ƙasa.^[196] Sojojin Japan sun fara shiga sassa na Indochina a watan Satumba na 1940, kuma a watan Yuli 1941 Japan ta tsawaita ikonta a kan dukkan Indochina na Faransa.{ Asar Amirka , da ta damu da fadada Japan, ta fara sanya takunkumi kan fitar da karafa da man fetur zuwa Japan daga Yuli 1940. Sha'awar tserewa daga wannan takunkumi da kuma zama mai dogaro da kanta a cikin albarkatun ya ba da gudummawa ga shawarar Japan na kai hari a ranar 7 ga Disamba, 1941. , Daular Biritaniya (a Hong Kong da Malaya ) da kuma Amurka lokaci guda (a cikin Philippines da Pearl Harbor, Hawaii).Wannan ya kai ga Amurka ta shelanta yaki da Japan a ranar 8 ga Disamba, 1941. Daga nan sai Amurka ta shiga bangaren daular Burtaniya, a yakin da ta yi da Jamus tun 1939, da kawayenta na yaki da masu karfin Axis.'Yan kwaminisanci na Indochine sun kafa hedkwatar sirri a lardin Cao Bằng a cikin 1941, amma yawancin juriyar Vietnam ga Japan, Faransa, ko duka biyun, gami da ƙungiyoyin gurguzu da na gurguzu, sun kasance a kan iyaka, a China.A matsayin wani ɓangare na adawa da faɗaɗa Jafananci, Sinawa sun ƙarfafa kafa ƙungiyar gwagwarmayar kishin ƙasa ta Vietnam, Dong Minh Hoi (DMH), a Nanking a 1935/1936;wannan ya haɗa da 'yan gurguzu, amma ba su da iko.Wannan bai samar da sakamakon da ake so ba, don haka jam'iyyar kwaminisanci ta kasar Sin ta aika da Ho Chi Minh zuwa Vietnam a shekara ta 1941 domin ya jagoranci wata kafa ta karkashin kasa mai ra'ayin gurguzu ta Viet Minh.Ho shi ne babban wakilin kwaminisanci a kudu maso gabashin Asiya, ^[197] kuma ya kasance a kasar Sin a matsayin mai ba da shawara ga sojojin kwaminisanci na kasar Sin.^[198] Hukumar leƙen asiri ta Turai ce ta taimaka wa wannan manufa, kuma daga baya Ofishin Ayyuka na Dabarun Amurka (OSS).^[199] Har ila yau, bayanan sirri na Faransanci ya yi ƙoƙarin rinjayar ci gaba a cikin haɗin gwiwar Vichy-Japan.A cikin Maris 1945, Jafananci sun ɗaure masu mulkin Faransa kuma suka mamaye Vietnam kai tsaye har zuwa ƙarshen yaƙin.