Rubuta ci gaba don wannan sakin layi - Alexander yayi ƙoƙarin shiga Rundunar Sojan Sama ta Amurka amma an ƙi shi saboda kawai ya sami ilimin makarantar sakandare kuma aƙalla ana buƙatar wasu ilimin kwaleji don sabis na USAAF. Ya shiga Royal Canadian Air Force a watan Oktoba na 1940 don shiga cikin yakin a matsayin matukin jirgi da kuma guje wa yin rajista da aikawa don yin aiki a cikin sojojin. A lokacin, yana da sa'o'i 25 ne kawai na kwarewar jirgin sama, wanda ya yi ƙasa da abin da ake buƙata na Royal Air Force (RAF). Ya sami fikafikansa a ranar 15 ga Satumba 1941 kuma an sanya shi zuwa Squadron 133 Eagle a Ingila. Kusan shekara guda daga baya, a watan Agusta 1942, Alexander ya shiga cikin Operation Jubilee
, wanda daga baya ya kira shi "ranar da ba za a iya mantawa da ita ba a RAF". A cikin manufa guda biyu a matsayin wani ɓangare na wannan aikin ya harbe jiragen saman Jamus guda biyu kuma ya lalata na uku.