Iran Update, March 31, 2025

Iran Update March 31, 2025

Kelly Campa, Ria Reddy, Ben Rezaei, Johanna Moore, Katherine Wells, Annika Ganzeveld, Alexandra Braverman, Andie Parry, Avery Borens, and Brian Carter

Information Cutoff: 2:00pm ET

The Critical Threats Project (CTP) at the American Enterprise Institute and the Institute for the Study of War (ISW) publish the Iran Update, which provides insights into Iranian and Iranian-sponsored activities that undermine regional stability and threaten US forces and interests. CTP-ISW publishes the Iran Update every weekday.

Click here to see CTP and ISW’s interactive map of the ongoing opposition offensive in Syria, and here to see CTP and ISW’s interactive map of Israeli ground operations. The Syria map is updated daily alongside the static Syria maps in this report. CTP-ISW ended daily maps of Israeli ground operations in February 2025.

We do not report in detail on war crimes because these activities are well-covered in Western media and do not directly affect the military operations we are assessing and forecasting. We utterly condemn violations of the laws of armed conflict and the Geneva Conventions and crimes against humanity even though we do not describe them in these reports.

Iran continues to threaten the United States with military action to dissuade the United States from a strike on Iranian nuclear facilities amid new US threats to strike the nuclear facilities. US President Donald Trump stated on March 30 that “there will be a bombing" if Iran does not make a new nuclear deal.[1] Trump added that he would impose secondary tariffs on Iran if Iran made no progress towards a deal.[2] Secondary tariffs would impose sanctions on countries that trade with Iran. US officials have previously threatened military action against Iran if there were no direct negotiations.[3] Iranian officials have said they are open to indirect negotiations, though they reject direct negotiations with the United States.[4] Senior Iranian officials have also repeatedly threatened to strike US interests in the region since at least January 2025, likely to shape US decision-making and discourage a US or Israeli attack on Iran's nuclear program.[5] An unspecified senior Iranian military official told the Telegraph on March 29 that Iran would attack any base "used by Americans" to attack Iran.[6] Iranian threats to attack US allies in the region may aim to discourage allies from allowing the United States to use their facilities out of fear of Iranian retaliation.

Iranian officials have recently threatened the following responses to a US-Israeli strike on Iran. These courses of action are not mutually exclusive.

• Attack US bases and forces: Iranian officials have repeatedly explicitly threatened to attack US bases and forces in the region in recent months.[7] An unspecified senior Iranian military official told Western media on March 29 that Iran would target Diego Garcia Island in the Indian Ocean if the United States attacked Iran.[8] The United States has recently increased its military presence at Diego Garcia Island, according to commercially available satellite imagery.[9] An anonymous official also told Tehran Times that Iran's missile launchers at its underground bases are loaded with missiles and "ready for launch."[10] Iran's reported current maximum missile range is 2000 kilometers (km), and its reported maximum drone range is around 2500km.[11] Diego Garcia Island is located about 3700km from Iran's southernmost city, Pasabandar. Iran would need to significantly decrease the payload of the warhead on its medium-range missiles or otherwise decrease missile weight to launch a successful attack on Diego Garcia. Iran could target other US facilities in the region if it chose to do so. Islamic Revolutionary Guard Corps (IRGC) Air Force Brigadier General Amir Ali Hajizadeh threatened on March 31 that US bases in the region are “sitting in a glass house" near Iran.[12]

• Disrupt international trade: IRGC Navy Commander Admiral Alireza Tangsiri suggested on March 29 that Iran may close the Strait of Hormuz if the United States and Israel attack Iran.[13] Tangsiri also threatened to seize ships if Iranian ships were seized.
• Conduct a direct attack on Israel: Senior Iranian military commanders have recently resurfaced threats to conduct another missile attack on Israel.[14] Iran unveiled its latest precision-guided ballistic missile called the “Etemad” in February 2025.[15] Iranian media referred to the missile as the “Israeli ballistic missile” because it can reportedly hit key targets across Israel.[16] Iran's stockpile of medium-range missiles, or missiles that can reach Israel, has been severely depleted following the April and October 2024 Israeli airstrikes on Iran, however.

Iranian officials have publicly stated that they are unwilling to make concessions to reach a new nuclear deal with the United States under President Trump's desired timeline or terms. Iranian sources stated that Trump’s March 5 letter to Iranian Supreme Leader Ali Khamenei included demands that Iran curtail its missile program and its role in supporting its proxies and partners in the Axis of Resistance.[17] A senior Iranian military official stated on March 29 that Iran will "never negotiate” on its missiles or the “capabilities” of the Axis of Resistance.[18] CTP-ISW previously assessed that Iran is unlikely to agree to curtail its missile program or the Axis of Resistance because to do so would cause it to lose the primary means with which it seeks to expel the United States from the region and establish itself as the regional hegemon. An unspecified senior Iranian source separately told a UK-based, Gulf-linked outlet that Trump's letter refers to the "zero enrichment" approach.[19] It remains unclear if Iran is willing to reverse significant progress on its nuclear program to meet the terms. Western media also reported in mid-March that Trump's letter set a two-month deadline to reach a new nuclear deal.[20] Prior negotiations for the 2015 nuclear deal, or Joint Comprehensive Plan of Action (JCPOA), took 20 months to negotiate.

Iran is likely rebuilding its solid-fuel propellant stocks after Israeli strikes damaged key production sites in October 2024.[21] The sanctioned Iranian cargo vessel Jairan, which is carrying sodium perchlorate, a chemical used to make solid missile fuel,...
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