Kammala jumla mai zuwa: A watan Agusta 1945, an nada Brown mataimakin shugaban ma'aikatan Sojoji na shida a karkashin Janar Walter Krueger. A matsayinsa na gogaggen jami'in ma'aikata, ya shiga cikin shirin Operation Downfall, wanda aka tsara don mamaye Japan. Duk da haka, da
Daular Japan ta mika wuya a ranar 2 ga Satumba, 1945, kuma an soke aikin. An ba Brown lambar yabo ta Bronze Star Medal saboda sa hannu a cikin shirin. Yayin da yake aiki a wannan matsayin, ya kuma shiga cikin aikin Japan.