The British and Soviet authorities allowed Reza Shah's political system to collapse and limited the constitutional government’s functions. They permitted Reza Shah's son, Mohammad Reza Shah Pahlavi to succeed to the throne.In January 1942 Britain and the USSR signed an agreement with Iran to respect Iran's independence and to withdraw their troops within six months of the war's end. In 1943, at the Tehran Conference, the U.S. reaffirmed this commitment. In 1945, the USSR refused to announce a timetable to leave Iran's northwestern provinces of East Azerbaijan and West Azerbaijan, where Soviet-supported autonomy movements had developed.
