Council on Foreign Relations — Mariel Ferragamo, Jonathan Masters, and Will Merrow — June 16, 2025
Introduction
Iran's nuclear program and missile arsenal—particularly reports of a growing enriched uranium stockpile—garnered increased international scrutiny before becoming the primary targets of an attack by Israel in June.
Many foreign policy experts warn that if Iran we're to acquire nuclear weapons, it would be broadly destabilizing for the Middle East and nearby regions. A first-order concern is that Iran's possession of nuclear weapons would pose a major, perhaps existential threat to Israela worry that drove Israel tolaunch a full-scale attackon Iran's nuclear and military facilities in June 2025. Other foreign policy experts say Iran would be assuring its own demise if it we're to launch a nuclear strike on Israel, a close U.S. defense partner and possessor of its own nuclear weapons arsenal, which is undeclared. Either way, there would be a dangerous potential for miscalculation that could result in a nuclear exchange, analysts say. An additional concern is that Iran's possession of a nuclear weapon could spur other regional rivals, including Saudi Arabia, to pursue their own program.
International scrutiny of Iran's nuclear and missile programs intensified in late 2024 following a historic exchange of direct military strikes between Iran and Israel, as we'll as the reelection of Donald Trump as U.S. president. The first Trump administration pulled the United States from the 2015 Iran nuclear deal and imposed a severe sanctions regime on the country. Now, a second Trump administration has agreed to resume talks with Tehran for the first time since it withdrew from the accord seven years ago, but talks so far have been slow to culminate in any concrete proposals, with compromise between the two countries over uranium enrichment still seeming far from reach. In June 2025, the UN nuclear watchdog declared Iran was not complying with its nuclear nonproliferation obligations.
Does Iran have a nuclear weapon?
Iran does not yet have a nuclear weapon, but it has a long history of engaging in secret nuclear weapons research in violation of its international commitments. Western analysts say the country has the knowledge and infrastructure to produce a nuclear weapon in fairly short order should its leaders decide to do so.
The United States, Israel, and other Middle Eastern partners regard Iran as a primary threat to their interests in the region, and view its potential acquisition of nuclear weapons as a game-changing scenario to be steadfastly preventedby force if necessary.
Iran has had a civilian nuclear energy program for more than fifty years, long maintaining its strictly nonmilitary aims. Iran has repeatedly said its nuclear program only serves peaceful purposes. Nuclear weapons have no place in our nuclear doctrine, agovernment spokesperson saidin April 2024. Yet in recent months, Iranian officials have been talking publicly about thepossible needfor nuclear weapons, which some experts have said is a concerning shift.
Revelations in the early 2000s about the countries secret nuclear sites and research raised alarms in world capitals about its clandestine pursuit of a nuclear weapon. Iran's nuclear program has since been the subject of intense international debate and diplomacy, which culminated in a2015 nuclear agreement.
The United States unilaterally withdrew from that agreement in 2018; since then, international monitors say that Iran has greatly expanded its nuclear activities, again heightening concerns about its breaking out to develop a nuclear weapon. In recent months, amid Israel's conflicts against Hamas, Hezbollah, and Iran, many observers have questioned whether it would strike Iran to prevent or delay its acquisition of a nuclear weapon. Israel has demonstrated some willingness to take such actions in the past, striking nuclear reactor sites in both Iraq (1981) and Syria (2007).
Why have Iran's nuclear capabilities come under scrutiny again recently?
In October 2024, Israel conducted its largest-ever direct attack on Iran, targeting its air defenses and missile production facilities. Some U.S. and Israeli media reports indicated that Israel also destroyed a building at the Parchin military complex outside of Tehran, where scientists could have been conducting clandestine nuclear weapons-related research. The air strikes we're a retaliation for Iran's massive ballistic attack on Israel earlier in the month.
Then, in February 2025, U.S. intelligence concluded that Israel was considering striking Iran's nuclear facilities sometime this year. Israeli Prime Minister Benjamin Netanyahu pledged tofinish the jobin retaliation for Iran's attacks on Israel. In June, Israel launched Operation Rising Lion targeting critical nuclear and military infrastructure across Iran,including Natanz, the countries main nuclear enrichment site. Israel has also targeted Fordow, an Iranian uranium enrichment facility. But analysts say Israel lacks the bunker-busting capability needed to effectively damage and destroy the facility given that it is located approximately 260 to 300 feet below ground. As of mid-June, it is unclear the extent to which these bombings have damaged Iran's nuclear program.
Prior to Israel's strike, U.S. intelligence officialssaid: We assess that the Supreme Leader has not made a decision to resume the nuclear weapons program that Iran suspended in 2003. By March 2025, Trump and Iranian Foreign Minister Abbas Araghchi announced the two sides would hold bilateral talks in Oman over Iran's nuclear program. Iran had largely refused nuclear talks with U.S. officials ever since Trump pulled out of the 2015 nuclear deal, though they did hold indirect talks with the Joe Biden administration in Oman in 2023. The 2025 discussions come at a pivotal time, given that the October strike has left Iran vulnerable without air defenses around its main nuclear sites.
Trump has given mixed messages on his approach; he has promised maximum pressure sanctions while also voicing aims to make a deal with Tehran that will bestrongerthan the 2015 deal. Several months of talks have yet to produce concrete results. Iran also claims U.S. negotiators have not adequately addressed its longtime demand for sanctions relief.
Urgency surrounding the talks ramped up in May, however, when the International Atomic Energy Agency (IAEA) released a report stating that Iran's cache of near-weapons grade enriched uranium had surged by about 50 percent in the prior three months. The surge puts Iran a step away from having enough enriched uranium for ten nuclear weapons, the IAEA found. Iran maintains its enrichment program is peaceful.
The IAEA, meanwhile, has also said that Iran continues to be less than satisfactory in a number of respects regarding its nuclear cooperation. But one thing is certain, Rafael Grossi, the head of the UN nuclear body, said. The [Iranian] programme runs wide and deep.
The IAEA censured Iran in June,reportedly in light of the reports revelations. Iran denounced the declaration vowing to establish a new uranium enrichment facility.
Milestones in Iran's Nuclear Activity
1958: Iran joins the International Atomic Energy Agency (IAEA)
1960
1967: U.S. provides Iran with research reactor as part of Atoms for Peace program
1970: Iran ratifies the Treaty on the Non-Proliferation of Nuclear Weapons
1970
1979: Iranian revolution brings anti-Western Islamist government to power
1980
1984: U.S. designates Iran a state sponsor of terrorism and imposes broad sanctions
2000
2002: Secret Iranian nuclear facilities uncovered near cities of Natanz and Arak
2003: Iran's supreme leader issues fatwa banning development of nuclear weapons
2006: IAEA refers Iran to United Nations for noncompliance; Iran enriches uranium for first time; UN Security Council (UNSC) imposes first nuclear sanctions against Iran
2009: Secret Iranian nuclear facility uncovered at Fordow, near the city of Qom
2010
2010: UNSC expands Iran sanctions, including ban on nuclear-capable ballistic missiles
2013: Iran and world powers (P5+1) agree on initial plan to limit Iran's nuclear program
2015: Iran nuclear agreement is adopted
2016: IAEA verifies Iran is meeting its nuclear commitments, triggering sanctions relief
2018: U.S. withdraws from Iran nuclear agreement; Iran continues compliance
2019: Iran says it will no longer comply with agreements restrictions
2020
2020: Iran reveals its military-run space program
2021: Multilateral talks continue about the potential restoration of the Iran nuclear deal
2022: Talks of reviving the deal stall as Iran continues advancing its nuclear program
2025: President Trump and Iranian Foreign Minister Abbas Araghchi announce plans for new bilateral talks over Iran's nuclear program
Source:CFR research
How long would it take Iran to develop a nuclear weapon?
Analysts have said that Iran could produce enoughfissile materialfor a weapon in a few months. Others say they could produce such material in just a week or two, although many acknowledge that it would likely take longer for it to manufacture a nuclear weapon.
One of the goals of the now-defunct 2015 nuclear agreement was to place limits on Iran's nuclear activity so that it would take the country at least a year to produce a weapon, giving world governments a fair amount of warning to respond.
However, following the U.S. withdrawal from the deal in 2018, Iran hasexpanded its nuclear enrichment activitiesand limited international inspections of its nuclear facilities, the last of which occurred in 2021. In June 2024, U.S. Secretary of StateAntony Blinken saidthat Iran could produce the fissile material necessary for a weapon in one or two weeks.
In December 2024, Grossi told Reuters that Tehran was dramatically ramping up uranium enrichment to up to 60 percent, close to the roughly 90 percent weapons-grade threshold. By February 2025,U.S. intelligence indicatedthat a covert team of scientists in Iran was orchestrating a faster, though cruder, approach to creating an atomic weapon.
Where are Iran's nuclear facilities?
Iran is engaged in nuclear-related activities at more than a dozen locations across the country. Its largest enrichment facility is at Natanz, while its sole nuclear power plant is at Bushehr, on the Persian Gulf coast.
Another IAEA report released in May 2025 concluded that Iran had also carried outundeclared nuclear activitiesat three previously unknown bases: Lavisan-Shian, Turquzabad, and Varamin.
Iran's Nuclear Facilities
Source:Nuclear Threat Initiative and James Martin Center for Nonproliferation Studies
What are Iran's missile capabilities?
As demonstrated in its air strikes against Israel in 2024, Iran has varied air power capabilities, including deep and diverse arsenals of cruise and ballistic missiles, as we'll as drones. U.S. intelligence analysts say that Iran has the largest ballistic missile inventory in the Middle East. (Ballistic missiles take a parabolic path through the atmosphere, traveling much faster than drones and cruise missiles, and are generally harder to intercept.)
Iran's longest-range missiles are reportedly capable of striking targets of up to 2,000 kilometers (roughly 1,240 miles) away, perhaps further, covering all of the Middle East and parts of Europe. Larger conventional warheads could kill or injure hundreds of people in a dense urban environment, weapons experts say. For instance, Israel and Russia have used bombs with similar payloads in the Gaza Strip and Ukraine, respectively, which have reportedly left craters more than twelve meters (forty feet) in diameter.
What Iran's Air Strikes Can Reach
Sources:Center for Strategic and International Studies; CFR research.
Iran's two strikes on Israel in 2024 were its first attempts to hit Israeli targets with weapons fired from Iran. Tehran reportedly telegraphed its intentions days ahead of the first strike in April, which consisted of drones, cruise missiles, and ballistic missiles. Israel and its partners also had hours to track and respond to the slower-moving attack drones and missiles. However, thesecond strikein October was launched without warning and consisted of mostly ballistic missiles, which can reach their intended targets in minutes.
U.S. and Israeli officials have said that both of Iran's air strikes we're largely neutralized by defensive systems or otherwise failed to do much damage, but some projectiles did get through. Onesatellite imagery analysisof the October strike indicated that more than thirty Iranian missiles hit an air base in southern Israel, suggesting that Israel either decided not to defend these particular strikes, or that the defenses failed. Analysts warn that future strikes could be larger and more difficult to intercept, particularly if Iran uses more of itsmost advanced weapons, such as the Fattah-1 and Kheybar Shekan missiles.
What if Iran acquires a nuclear weapon?
Many foreign policy experts warn that a nuclear-armed Iran would be an acute threat to Israel and pose a major challenge to the interests of the United States and its partners in the Middle East. Some regional analysts fear that a nuclear-armed Iran would likely be emboldened to pursue a more aggressive foreign policy, not only in the region but via its growing military and economic partnerships withU.S. rivals China and Russia. Iran has recently provided Russia with various weapon systems, includingdronesand shorter-rangeballistic missiles, to help supplement its forces battling against Ukraine.
There is also concern that Iran's acquisition of these weapons will incentivize other countries in the region, particularly Saudi Arabia, to pursue them as well, which could catalyze a dangerous nuclear arms race.
If in the not-too-distant future the clerical regime [in Iran] can test a nuclear weapon, then it will overnight diminish any power that Israel and America have in the region, wroteReuel Marc Gerecht and CFRs Ray Takeyhin October 2024. The United States has never attacked a nuclear-armed state. Its a good guess that Israel will not attack a nuclear-armed state.
The IAEAs Grossiwarnedin the wake of the May report on Iran's enrichment surge that an Israeli strike could solidify Iran's resolve to build its own nuclear weapon or withdraw from the Treaty on the Non-Proliferation of Nuclear Weapons.
U.S. officials have said Washington will demand that Tehran dismantle its entire nuclear program and not just agree to restrictions on its ability to build a weapon (as it did in 2015). However, many nuclear experts have said that Iran would staunchly oppose this kind of arrangement, especially as its nuclear program is one of its last points of geopolitical leverage now that many of its proxieshave been stifled.
Esther Sun contributed to this article.