Rubuta ci gaba ga wannan sakin layi - A farkon 1942, Schrier ya shiga cikin 2nd Marine Raider Battalion a Camp Elliott, San Diego, an ci gaba da shi a matsayin sajan platoon a watan Afrilu 1942. A watan Yunin 1942, ya kasance wani ɓangare na kamfanoni biyu na 2nd Raider Battalion da aka aika zuwa tsibirin Midway
don ƙarfafa garkuwar can. Ya shiga cikin yakin Guadalcanal kuma ya sami kansa yana shiga cikin "Long Patrol" na 2nd Marine Raider Battalion a bayan layin abokan gaba daga Nuwamba zuwa Disamba 1942. A lokacin wannan aikin, ya bambanta kansa ta hanyar jagorantar wani ɓangare na kamfaninsa da aka yanke zuwa aminci bayan kwamandan kamfaninsa ya ɓatar da su cikin halin da ake ciki. A farkon 1943, an ci gaba da shi zuwa na biyu a filin. Daga bisani, an raba shi zuwa wasu ayyuka a cikin kungiyar Raider, irin su kallo da kuma bincike a kan tsibirin da aka yi wa abokan gaba kafin manyan raka'a suka kai hari. An ba shi lambar yabo ta Legion of Merit don aikinsa a Tsibirin Vangunu yayin Yaƙin New Georgia a watan Yuni na 1943. Ya kuma yi aiki a Bougainville don tallafawa ayyukan soja a can. A watan Fabrairun 1944, bayan da aka rushe Marine Raiders, ya koma Amurka don zama mai koyar da 'yan bindiga a sansanin Marine Corps Base Camp Pendleton. An sanya shi a matsayin jami'in zartarwa na Kamfanin E, 2nd Battalion, 28th Marine Regiment, 5th Marine Division. A watan Satumba, 5th Division ya bar Camp Pendleton zuwa Hawaii, don ƙarin horo. A cikin Janairu 1945, Rukunin 5th ya bar Hawaii don kai hari da kama Iwo Jima.