Sorry Kent your argument is slightly wrong & simplistic. The anglo-Soviet invasion did not include the U.S. It was the British other CommonWealth powers & the Soviet Union. Its purpose in 41 was to keep oil flowing the Soviet Union to fight Nazi Germany. After the war we the U.S. helped restore the same constitutional monarchy with the elder Shah’s son the one we know of today. (Read Norman Schwarzkopf autobiography his father was part of that effort.