Rubuta ci gaba don wannan sakin layi - A ranar 7 zuwa 8 ga Disamba, 1941, harin Japan a kan Pearl Harbor ya biyo bayan mamayewar su na Malaya
kuma, a ranar 8 ga watan, Churchill ya ayyana yaƙi da Japan. Bayan kwana uku sai Jamus da Italiya suka yi wa Amirka yaƙi. Churchill ya tafi Washington daga baya a cikin watan don saduwa da Roosevelt don taron farko na Washington (sunan lambar "Arcadia"). Wannan yana da mahimmanci ga "Turai na Farko", yanke shawara don ba da fifiko ga nasara a Turai a kan nasara a cikin Pacific, wanda Roosevelt ya ɗauka yayin da Churchill ke tsakiyar Atlantic. Amurkawa sun yarda da Churchill cewa Hitler shi ne babban abokin gaba kuma cewa cin nasarar Jamus shine mabuɗin nasarar Allied. An kuma amince da cewa na farko hadin gwiwa Anglo-American buga zai zama Operation Torch, mamayewa na Faransa Arewacin Afirka (watau, Algeria da kuma Morocco). Da farko an shirya shi a lokacin bazara na 1942, an kaddamar da shi a watan Nuwamba na 1942 lokacin da aka fara yakin El Alamein na biyu.