Kammala jumla mai zuwa: Bayan Harin Japan a kan Pearl Harbor da kuma shigar da Amurka a cikin yakin duniya na biyu, an sake kiran Foster zuwa aikin aiki tare da mukamin Kwamandan a cikin Naval Reserve kuma shugaban kasar Franklin D. Roosevelt ya ba shi aikin kai tsaye don gudanar da bincike na musamman na jirgin ruwa. Daya daga cikin ayyukansa na farko shi ne gudanar da bincike a cikin
Yankin Canal na Panama ya biyo bayan jerin korafe-korafe daga Laftanar Janar Daniel Van Voorhis, Kwamandan Rundunar Tsaro ta Caribbean a kan hadin gwiwar Sojoji da Sojojin Ruwa.