On June 13, Israel launched an unprecedented attack on Iran’s nuclear and military targets. The attacks are ongoing, but explosions have been reported across the country, including in Tehran, Natanz, Tabriz, and Karmanshah. The attacks killed key Iranian nuclear scientists, military leaders, and representatives overseeing U.S. nuclear talks, including Mohammad Bagheri, Gholamali Rashid, Hossein Salami, and Ali Shamkhani.
While Israel has a history of counterproliferation strikes on adversaries’ nuclear facilities, this attack is unique in its scope and timing. What the recent attack means for Iran’s nuclear program and nuclear risks in the region will depend on three main factors: (1) the success of the Israeli strikes and continued campaign in eliminating key components of Iran’s nuclear program; (2) the international response, including from Moscow and Beijing, who may take the position that the strikes undermine prospects for a diplomatic solution; and (3) geopolitics and stability in the region, which will influence whether or not Tehran perceives a need for a nuclear weapons program in the future.
Q1: Which parts of Iran’s nuclear program did Israel strike?
A1: The objective of the Israeli strikes appears to be not only to slow Iran’s immediate progress, but also to impose a longer-term setback by removing expertise and key assets that will be difficult to rebuild. Unlike the surgical strikes on Iraq in 1981 and Syria in 2007, which were each characterized by one precisely targeted attack, this was a wide decapitation move, including multiple nuclear sites.
The attack hit one of the key sites in the Iranian nuclear program: Natanz, a uranium enrichment plant roughly 140 miles south of Tehran. The site hosts some of Iran’s most sophisticated centrifuges, used to enrich uranium to high levels, and has been targeted multiple times in the past, including in 2010 and 2021. While the damage is still difficult to assess, Iran’s Atomic Energy Organization reports that the strike caused surface-level damage with some contamination inside the site. Additionally, International Atomic Energy Agency (IAEA) Director General Rafael Grossi confirmed that the Natanz site had been severely damaged, but that “there are no elevated radiation levels.”
Israel also attacked at least six military bases around Tehran, including Parchin, a suspected nuclear site that the IAEA has not been able to visit. In addition, the strikes hit the Khondab reactor, which has the potential to produce plutonium for a nuclear weapon, and the Kermanshah ballistic missile site. On Friday, explosions were reported in the city of Tabriz, the site of another nuclear research center and military bases.
Fordow, a second, key enrichment site near the city of Qom, appears to have been spared in the initial round of attacks. The facility is deep inside a mountain and difficult to destroy. The Bushehr Nuclear Power Plant and the uranium conversion facility in Esfahan—the latter of which produces uranium hexafluoride for enrichment and stores enriched uranium—had not been impacted at first either. It remains unclear whether Iran’s stockpiles of 60 percent and 20 percent enriched uranium were targeted.
The attack also killed several prominent nuclear scientists, including Mohammad Mehdi Tehranchi and Fereydoun Abbasi. Tehranchi, a physicist and president of Islamic Azad University, contributed to nuclear research and oversaw scientific education initiatives. Abbasi, previously targeted in a 2010 plot, was the former head of the Atomic Energy Organization of Iran. Numerous other scientists contributing to Iran’s nuclear research were also killed.
Q2: Can Israel take out Iran’s nuclear program without U.S. assistance?
A2: Given the dispersed and hardened nature of Iran’s key nuclear facilities, Israel may struggle to eliminate all components of Iran’s nuclear enterprise without U.S. assistance. Reaching some deeply buried structures would likely require support from the United States, which possesses the advanced Massive Ordnance Penetrator GBU-57, one of the few munitions capable of penetrating hardened targets. Israel announced that this is a multi-stage operation, likely to include additional attacks on the nuclear program. Through repeated attacks and the assassination campaign, Israel may be able to significantly set back Iran’s nuclear ambitions. Israel has a track record of bold, innovative operations, including cyberattacks, assassinations, and deception campaigns, and should not be underestimated.
Q3: Why did Israel choose to strike Iran’s nuclear facilities now?
A3: The timing of the operation was likely influenced by the IAEA’s announcement that Iran was no longer in compliance with its nuclear obligations under the Non-Proliferation Treaty (NPT), yesterday’s expiration of President Trump’s deadline for a nuclear agreement, and a closing military window to target vulnerable nuclear facilities. Additional regional factors also likely influenced the decision, such as the relative weakness of Hezbollah and Iranian proxies in the region.
The Joint Comprehensive Plan of Action (JCPOA), signed in 2015 between Iran and the P5+1 (China, France, Germany, Russia, the United Kingdom, and United States), stipulated that Iran could only enrich uranium up to 3.67 percent, was required to reduce its stockpile of low-enriched uranium, and agreed not to build any heavy-water facilities for 15 years. The United States withdrew from the JCPOA in 2017, citing concerns about its sunset provisions and exclusion of Iran’s ballistic missile tests and proxies. In April of his second term, President Trump restarted direct negotiations with Iran to establish a new agreement, setting a two-month deadline for negotiations on June 12.
The United States and Iran had the sixth (and final) round of talks scheduled for Sunday in Oman, but Tehran had yet to formally respond to Ambassador Steve Witkoff’s proposed framework for a deal by Trump’s deadline. Iranian state media reported on Friday that Iran will no longer participate in Sunday’s talks. The primary sticking point in the negotiations was Iran’s insistence on continuing to enrich nuclear material, which it has the right to do for peaceful purposes under the NPT. Conversely, the U.S. position was that Iran could not continue to enrich. Additional challenges in the negotiations centered on how to deal with Iran’s stockpiled fissile material.
While U.S. officials publicly distanced themselves from potential Israeli strikes, Netanyahu’s aides interpreted recent conversations with the United States as a “green light” for the strikes and an acknowledgement of the deteriorating negotiations. Those conversations included Netanyahu’s Monday call to brief Trump on the operation and Kristy Noem’s request two weeks ago that Israel delay its attack by a week.
Q4: Does this mean that Iran will give up its nuclear ambitions?
A4: Probably not. Counterproliferation strikes have a mixed historical record. On the one hand, the 2007 Israeli strikes on Al-Kibar were successful in shutting down Syria’s nuclear activities. On the other hand, the 1981 Osirak strike spurred Iraq to ramp up its nuclear weapons program. Indeed, as nuclear expert Målfrid Braut-Hegghammer has demonstrated, counterproliferation strikes can increase drivers of proliferation. Whether or not Iran abandons its nuclear ambitions will depend on at least three key factors.
First, it will depend on how successful Israel was in taking out Iran’s nuclear facilities. If key sites like Fordow and Esfahan are not severely damaged in future strikes and underground advanced centrifuges remain operational at Fordow and Natanz, Iran could continue its nuclear development. The success of the Israeli strikes will depend on whether or not it supplements airstrikes with covert methods and sabotage, and whether or not the United States changes position and provides direct support and ordnance. A TruthSocial post by President Trump suggests that Washington could support Israel if Iran does not come to the talks on Sunday.
Second, Iran’s path forward depends on what the international response to the attacks—in the region, as well as from Moscow, Beijing, and the wider international community—will be. On Friday, Russia condemned the Israeli strikes as unprovoked and a violation of the UN charter. China echoed concerns, with Foreign Ministry spokesman Lin Jian stating that “China is highly concerned about Israel’s attacks on Iran and deeply worried about the potential serious consequences of these actions.” Both Russia and China were party to the JCPOA, and Moscow recently offered to remove Iranian nuclear material and convert it for civilian purposes to overcome one of the hurdles in the ongoing U.S.-Iran talks. If Iran emerges from this crisis as the perceived victim, the international community could insist on Iran’s right to enrichment, albeit for peaceful purposes.
A final factor that will determine Iran’s nuclear future concerns geopolitics in the region—namely, whether or not Iran perceives a strategic need to develop a nuclear weapon. Arguably, nuclear weapons are primarily intended to defend against existential threats when the survival of the state is at risk. Israel’s strikes, along with any potential subsequent regional conflict, could prompt the leadership in Tehran to view its survival as threatened, potentially strengthening its resolve to pursue nuclear weapons for self-defense and deterrence.
Q5: What does this mean for wider nuclear risks, such as proliferation, and the international nuclear regime?
A5: Iran was testing the global nuclear order for decades with its enrichment to 60 percent, which is well beyond the percentage required for civilian peaceful purposes. It is worth emphasizing that immediately prior to Israel’s strike, the IAEA stated that Iran was not complying with its nuclear nonproliferation obligations and passed the first resolution against the country in 20 years. Iran had also announced last week the opening of a new uranium enrichment site. But Iran is not the only country that has been testing the nuclear regime in recent years.
Russia has been expanding its nuclear arsenal, particularly dual-capable intermediate-range systems, and relying on nuclear threats throughout the war in Ukraine. China has been rapidly expanding its nuclear arsenal and could have 1500 nuclear weapons by 2035. At the same time that nuclear arsenals and nuclear risks are rising, guardrails and risk reduction tools are falling apart. Russia has violated at least nine nuclear arms control agreements since Putin came to power in 2000. Although the 2010 New Strategic Arms Reduction Treaty with Russia is due to expire in February 2026, Moscow rebuffed numerous invitations from the Biden administration to engage in dialogue and has been wildly erratic in its messaging about arms control since Trump’s inauguration. China has consistently refused to engage in strategic arms control dialogue. The nuclear order is at its weakest point since the early days of the Cold War.
These strikes and Iran’s response also have the potential to further undermine the international nuclear regime and the NPT, which is typically seen as the cornerstone of the global nuclear order. In recent years, the NPT has struggled to reach consensus on key issues. One area where the NPT remained relatively successful was in monitoring and allowing for peaceful uses of nuclear technology, which was Iran’s justification for nuclear enrichment. Iran’s enrichment activities were already testing the strength of the NPT and nonproliferation norms.
Finally, the strikes will further complicate, if not completely undermine, hopes for a diplomatic solution to Iran’s nuclear ambitions. The failure of diplomacy will have repercussions beyond Iran. If Iran does rebuild its nuclear program and aggressively pursues a weapons program in the aftermath of the strikes, it could prompt other states in the region to pursue nuclear programs or start a proliferation cascade. Israel’s strikes should be seen as a unilateral verdict on the failure of the NPT and nuclear restraint. Iran’s ability to rebuild a nuclear program and future proliferation risks will also depend on whether or not that regime can survive the months and years ahead.
Heather Williams is the director of the Project on Nuclear Issues and a senior fellow in the Defense and Security Department at the Center for Strategic and International Studies (CSIS) in Washington, D.C. Doreen Horschig is a fellow with the Project on Nuclear Issues at CSIS. Bailey Schiff is a program coordinator and research assistant with the Project on Nuclear Issues at CSIS.
