Following the assassination of Ali Larijani, Iran has appointed Mohsen Rezaei, a former commander-in-chief of the Islamic Revolutionary Guard Corps (IRGC), to head its Supreme National Security Council. This move comes amid ongoing negotiations over the Strait of Hormuz, a strategic waterway through which a fifth of global oil and gas passes. The appointment was announced by President Masoud Pezeshkian on Sunday evening, with Iran's supreme leader, Mojtaba Khamenei, issuing a decree designating Rezaei as his representative on the council. Rezaei, 71, served as commander of the IRGC from 1981 to 1997 during the Iran-Iraq War and subsequently became a member of the Expediency Discernment Council, a body that resolves disputes between parliament and the Guardian Council. The appointment is significant given Rezaei's extensive military, economic, and political experience, as well as his role in Tehran's negotiations with the US. Additionally, Rezaei's positioning ahead of the 2024 presidential election may provide him with leverage among various factions within the conservative camp, including Pezeshkian's government, the conservative camp linked to current parliament speaker and chief negotiator Mohammad Bagher Ghalibaf, and military and security forces with which Rezaei has a history. The Supreme National Security Council serves as a key institution where strategic considerations from the presidency, foreign ministry, armed forces, and security agencies intersect, making Rezaei's appointment a notable development in Iranian politics amidst escalating regional tensions.