 There was a major reorganisation in April 1945 for the planned invasion of Japan . All Army forces in the Pacific were placed under MacArthur 's command , including those in Nimitz 's Pacific Ocean Areas . A new command was formed , Army Forces Pacific ( AFPAC ) , with GHQ operating as the headquarters of both AFPAC and SWPA . Units in POA remained under Nimitz 's operational control , and the first major formation , the Tenth United States Army , did not pass to AFPAC control until 31 July 1945 . SWPA , together with the Allied Air Forces , Allied Naval Forces and Allied Land Forces , was abolished on 2 September 1945 , but GHQ remained as GHQ AFPAC . 
