Did Truman threaten a nuclear strike if the Soviet Union didn't withdraw from Iran in 1946?

Question

In episode 4 of Oliver Stone's documentary series, *Untold History of the United States*, Stone claims that then-president Truman issued an ultimatum to the Soviet Union: either withdraw from Iran (which was partly occupied by the Soviet Union in 1946) or face a nuclear strike. [My googling](https://www.history.com/this-day-in-history/soviets-announce-withdrawal-from-iran) did not result in a reliable source; on the contrary, it seems that Truman was merely bragging about his power in private, and the real reason for the Soviet withdrawal might have been that they managed to obtain oil concessions from Iran. Did Truman really threaten a nuclear strike or was he just bragging?

Answer 1

I would say this is doubtful, considering he brought American soldiers into Korea instead of using the H-bomb. That war was unpopular at the time and Eisenhower promised on the campaign trail to "go to Korea" if elected.