American plans to use air bases in the USSR began as United States Army Air Forces ( USAAF ) staff studies soon after the German invasion on 22 June 1941 . After the Japanese attack on the United States on 7 December , the concept was expanded to hit the Japanese Home Islands from Siberia . However , Soviet air cooperation was negligible through 1942 , and it was not until the Foreign Ministers ' conference ( Moscow Conference ) in Moscow in October 1943 that the American delegation raised the issue formally with Foreign Commissar Vyacheslav Molotov
Moscow Conference
Moscow Conference (1942)
Operation Frantic