Kammala jumla mai zuwa: Bayan shigar Amurka cikin Yaƙin Duniya na II, O'Neil ya shiga cikin kare kogi daga yiwuwar harin Japan, wanda ya faru tsakanin Yuni 4 <unk> 7, 1942. Domin rawar da ya taka a
Yaƙin Midway, O'Neil an yi masa ado da lambar yabo ta Bronze Star tare da Combat "V". An kuma daukaka shi zuwa matsayin dan lokaci na Lieutenant Colonel a ranar 7 ga Agusta, 1942.