 Otherwise, at the end of that deadline, Iran would exceed the limits on its stockpile of enriched uranium.In September 2019, as a third major step to scale down commitments to the 2015 nuclear accord, after another 60-day deadline, Iran nullified all limits on nuclear research and development.On 21 April 2019, a few days before United States sanctions were due to take effect, Iran Supreme Leader Ali Khamenei appointed Hossein Salami as the new commander-in-chief of the Islamic Revolutionary Guard Corps (IRGC).