The talks over the revival of the 2015 Iran nuclear deal, known as the Joint Comprehensive Plan of Action (JCPOA), have so far proven difficult. In December 2021, after Iran played hardball in Vienna, U.S. Secretary of Defense Lloyd Austin, in a meeting with his Israeli counterpart in Washington, announced that the Biden administration is “prepared to turn to other options” to halt Tehran’s nuclear program if diplomatic talks fail to do so. The White House also confirmed that President Joe Biden has ordered his staff to prepare “additional measures.” Media reports on the U.S.-Israeli discussions revealed that the “other option” is said to be a joint military strike on Iran’s nuclear facilities.

In early January 2022, however, things started to change. Iran’s agreement with the International Atomic Energy Agency (IAEA) to reinstall monitoring cameras at the Karaj nuclear facility and the U.S. assessment of modest progress in the Vienna talks brought back hope for a diplomatic solution. Also, the Israeli position toward a U.S. deal with Iran dramatically shifted. Foreign Minister Yair Lapid said Israel is not against any agreement and “a good deal is a good thing.” Yet the debate about military options is still ongoing in Tel Aviv despite significant disagreements on the issue between the Israel Defense Forces (IDF) Intelligence Chief Maj. Gen. Aharon Haliva and Mossad Director David Barnea.

Several questions are critical in this debate. Will the U.S. secure a longer and stronger non-proliferation objective by carrying out a military strike on Iranian nuclear facilities? Will the strike be able to convince the Islamic Republic’s leadership to abandon sensitive parts of its nuclear program, if not the whole program? Given the limits of military strikes, is the threat of war a meaningful strategy and does it pose a credible threat to Iranian leaders? What would be the consequences for the U.S.’s future ability to respond if Iran decides to speed up a new weapons program after the strike?

Debates on a military solution to Iran’s nuclear program are heavily polarized between those arguing that a threat of war and a preventive non-proliferation military strike can be a solution and those arguing that military action will only accelerate Iran’s nuclear program. This difference of opinion is also at the core of the divergence in U.S. and Israeli intelligence assessments.

The truth is that it is highly unlikely that Tehran would abandon its nuclear program after a military strike. There are serious operational limits to the success of such an operation that at the end would enable Tehran to restart key areas of its nuclear activity, likely shortly after the attack. Besides, the domestic costs of abandoning the nuclear project would be steep; it would be, in effect, political suicide for Supreme Leader Ayatollah Ali Khamenei. While no major change in the political-military elites who decide on Iran’s nuclear decisions has taken place, it is unreasonable to believe that Iranian leaders will trust the U.S. enough to abandon a program in which they have already invested heavily. On the contrary, a military strike will be a catalyst to build up an assessment in favor of the security benefits of having a nuclear bomb, ultimately exacerbating non-proliferation dynamics in the Middle East.

While the argument is often made that time is running out to reach an agreement, in reality the parties are constrained by a lack of options and are bound to a diplomatic resolution of the crisis as the only rational choice available.

Tactical ambiguities

A quick review of previous Israeli counter-proliferation strikes may be helpful. The IDF attack on the Syrian nuclear site in Deir ez-Zour in September 2007 benefited from a short decision and operation cycle. Starting in late 2006, the planning and execution of the strike proceeded under tight secrecy, which provided a major element of surprise. The Syrian nuclear site only relied on camouflage and concealment because Bashar al-Assad had calculated that secrecy would provide the most protection for the project. This assessment made the project vulnerable to intelligence disclosure. Not only did the Syrian reactor not have surface to air missile (SAM) protection, but it was also only moderately armored and located above ground.

The Osirak reactor in Iraq, targeted in an Israeli strike in 1981, was a similarly soft and solitary target. In addition to Iraq’s poorly prepared SAM systems, the Israeli strike came in the midst of the Iran-Iraq war, at a time when Iraq’s centralized air-defense systems were constantly saturated due to Iran’s heavy aerial bombardment. This gave Israel the possibility of covering up the attack as well as vital tactical surprise about its direction.

None of these conditions match Iran’s current situation, and a U.S.-Israeli attack would take place in a fundamentally different strategic environment. First, bombing Iran’s nuclear facilities would have no element of surprise. For years, U.S. presidents and international security experts have been analyzing such a scenario. Plans on how Israel might attack Iran were even published by Yoaz Hendel in his 2012 book titled Israel vs. Iran: The Shadow War. Both today and back in 2011-12, when diplomatic negotiations proved bumpy, the threat of a military strike was a fixed part of the U.S. negotiating strategy. Tehran has had more than enough time to prepare and formulate a well-developed counter-strike plan. In fact, Tehran has specifically designed its key nuclear facilities, such as Fordow, to withstand such a strike.

Second, Tehran’s strategy has been to combine active and passive defense measures as part of its readiness plan. Its research, centrifuge production, uranium mining and processing, and possible weapons production facilities are widely dispersed across the country. Moreover, they all benefit from various levels of hardening, air-defense systems, and electronic warfare measures. Natanz is located 20 meters below ground and Fordow is buried under 80 meters of rock in the mountains. These are hard and deeply buried targets (HDBT), which complicates targeting and operational planning and negatively impacts operational success rates.

Third, there is a major intelligence gap about the level of hardening in Fordow and Natanz. Experts have already raised doubts about whether a single U.S. 30,000-pound Massive Ordnance Penetrator (MOP), or “bunker buster” bomb, which is the main conventional option, can penetrate and inflict sufficient damage on these facilities. Optimistic assumptions rely on a set of incomplete intelligence assessments. Yet there is little data on actual redundancy levels and extra hardening at these sites, and particularly on new upgrades that Iran may have carried out after the MOP became operational — measures that might help to withstand the newly upgraded U.S. MOP. Thus, guaranteeing that a strike would render Fordow dysfunctional for a meaningful period of time from a non-proliferation perspective is extremely difficult.

And fourth, for the above reasons, the operation is deemed to be a large-scale military campaign. According to the Congressional Research Service, the Israeli or U.S. air force would require hundreds of aircraft and thousands of sorties to deliver enough bombs on multiple targets as well as maintain operational sustainability to conduct a post-strike assessment of success. In addition, HDBT targets, especially Fordow, might require more than one strike to ensure effective destruction.

In other words, the U.S. and Israel would also need to design a plan to blind Iran’s national air-defense system across the whole country given the depth of the nuclear sites inside Iran. However, Tehran has heavily invested in air-defense systems too. It has made them geographically dispersed, has created decentralized passive SAMs resilient to jamming, has improved its electronic warfare capability with Russian help, and is using unknown indigenous batteries. It operates a multi-layered architecture of short to long range, homemade to imported versions of SAMs. There is little data about their operational capabilities and some versions, such as the Bavar-373 and new 3-Khordad SAM systems, are mostly unknown, although the 3-Khordad did shoot down a U.S. RQ-4A in 2019. Suppressing these assets is in no away a small-scale operation like the Syrian and Iraqi cases. In a scenario in which Tehran’s strategy relies on forward air suppression by using Syrian and Iraqi territory to hit Israeli jets, the situation will become even more complicated.

This makes any surgical air campaign unrealistic. Tehran has warned about a crushing response and in its latest “Great Prophet” drills has signaled its own version of a plan to strike back against Israeli nuclear sites. This means U.S. and Israeli planners will also need to find a way of neutralizing Iran’s second-strike capability. All of this adds up to a recipe for a full-scale war scenario that is in no way comparable to the low-cost Israeli operations in Iraq and Syria. Recent debates have highlighted the limits of Israel’s military capabilities to carry out such a scenario, while the odds of tactical success remain questionable. Indeed, the high costs and uncertain non-proliferation value of such a strike substantially undermine the credibility of the “threat of war policy” as a negotiating tactic.

Iran may build back better

Unlike the Iraqi case, which received less international public attention, probably because it occurred in the midst of Saddam Hussein’s war with Iran, the Iranian nuclear program is a highly public matter. Syria’s nuclear reactor was also hit in complete silence by a deniable Israeli attack. It raised minimum political costs for Assad. Israeli planners were smart to consider the fact that if the attack avoided embarrassing and humiliating Assad publicly, there was a reasonable chance he would decide to hold back and not respond.

By contrast, Tehran has already invested billions of dollars as well as major political capital in its nuclear projects. In domestic propaganda, Iran’s nuclear capability has been deemed a source of national pride and one of the revolution’s key successes. Above and beyond the humiliation that a strike would cause, an immediate policy shift in its aftermath would have major political costs for the Islamic Republic as well. The leadership’s restraint would not be a face-saving strategy since there would be no plausible deniability for the U.S. or Israel. Thus, the public humiliation caused by attacks on Iranian nuclear sites would inevitably put Supreme Leader Khamenei under huge political pressure to react.

Iran’s response is likely to be two-fold and involve both a military and a nuclear response. But as I have shown in earlier case studies, Iranian behavior follows a core logic of “balancing the threat” and “escalating to deescalate.” As was evident in 2011-12 and the 2019 tensions in the Strait of Hormuz, a growing assessment of existential threats causes Tehran to distance itself from conservative policy pursuits and instead adopt a brinkmanship strategy to reveal the risks of its competitors' policy and convince the aggressor of the mutual costs of insecurity. Tehran’s response to several acts of Israeli nuclear sabotage since 2020 has followed a similar logic.

Iran’s response to the assassination of Mohsen Fakhrizadeh on Nov. 27, 2020 was a mix of political, legislative, technical, and restrictive measures that ultimately resulted in the expansion of its nuclear activities. As the International Crisis Group reports, this included a bill in the Iranian parliament mandating “the initiation of 20 per cent uranium enrichment and annual accumulation of 120kg at that level; 500kg of monthly enriched uranium production; installation of additional IR-2 and IR-6 centrifuges; launch within five months of a uranium metal factory, work on which has commenced; preparation for reverting the Arak heavy-water reactor to its pre-JCPOA configuration; and suspending implementation of the Nuclear Non-Proliferation Treaty’s Additional Protocol should other JCPOA signatories provide no sanctions relief within two months of the law’s enactment.”

The response to sabotage at the Natanz facility in April 2021 was a similar decision to go for 60% uranium enrichment and rebuild a new protected workshop in a tunnel under the mountain. Indeed, the attack provided Tehran a unique opportunity to test its technical capabilities for enrichment closer to weapons-grade level and make its facilities resistant to possible future sabotage attempts. Iran’s response following sabotage at the Karaj centrifuge production plant on June 23, 2021 was guided by a similar logic too. The sabotage damaged the facility and halted its production but also blinded IAEA cameras. But after resuming activities at the site almost two months later, the IAEA was barred from installing new cameras. Again, Tehran attempted to impose a cost on the aggressor for the sabotage by benefiting from several months of unmonitored activities.

In this way, the Islamic Republic’s leaders have shown their ability to forge a domestic consensus and a political willingness to ratchet up tensions and use brinkmanship when threats to the regime are high. Tehran’s indigenous nuclear know-how enables it to rebuild the destroyed facilities and build back a stronger program. That said, it can be argued that Tehran’s response might involve more than just a number of tactical measures, restrictions on the IAEA, or even revisiting the Nuclear Non-Proliferation Treaty.

Would a military strike strengthen the rationale for Iran’s nuclear bomb? The answer to this question seems to be positive. A military attack might radically change Iranian elites’ calculus of their security environment. CIA Director Bill Burns made it clear that he does not believe Iran's supreme leader has decided to take steps to weaponize a nuclear device. Yet a strike could dramatically change the regime’s assessment of immediate security threats by proving that it is unable to deter enemy aggression with conventional means amid a growing threat environment. So far, the military escalations since 2019 have gradually spurred public debate about the need for a nuclear bomb among Iranian experts and Persian media outlets.

The Amad project, Iran’s nuclear weapons program in 1990s, was motivated by a similar assessment. Such an assessment would facilitate forging a consensus among political-military elites to opt for a nuclear deterrent and a strategic defense capability. History suggests that Iraqi elites reached a similar conclusion after the Israeli attack on Osirak. It intensified Baghdad's commitment to acquiring nuclear weapons and created independent bureaucratic momentum toward weaponization and vested interest in the development of a nuclear weapons capability.

On the other side, there is no guarantee that the strike would increase the domestic obstacles to Iran’s nuclear program. Ironically, it might actually minimize such obstacles and justify the suppression of those with opposing ideas among the elites. Resolving the existential threats facing the revolution would then be linked to a nuclear device. This could be the moment that Iran’s supreme leader would have enough of a reason to changes his fatwa in favor of a nuclear bomb.

The wider strategic consequences

A military solution to Iran’s nuclear dispute might risk the U.S. shift to focus on great power competition as well. If Tehran decides to build back its nuclear program better and moves toward the bomb, then the U.S. will find itself in a repeated cycle of intelligence and military actions against Iranian nuclear facilities. The complexity of intelligence operations to locate and identify new Iranian sites will increase in a post-strike scenario in which the IAEA’s monitoring ability will probably be limited. At the same time, unification of bureaucratic and scientific bodies at the national level might increase the speed of Iranian activities and add to the complexity of intelligence assessments. Moreover, the Islamic Revolutionary Guard Corps now has a better technical capability and more experience in building deeply buried structures than it did when Fordow was built before 2007. That means Iran’s future nuclear facilities would likely incorporate new and more sophisticated passive defense measures and be better concealed, deeper, and harder to destroy. This new operational and intelligence situation would in turn create further complications for a future U.S. conventional strike capability and force the Pentagon and the Intelligence Community to devote more resources to the issue — resources that would not be devoted to strategic competition with China and Russia.

At the same time, reaching a political deal with Tehran in a post-strike environment would be even harder. Tehran will calculate that even if it agrees to the U.S. demands, the future U.S. response might still include military intervention. In an atmosphere of mistrust between the U.S. and Iran, the value of complying with U.S. demands will continue to remain uncertain in the Iranian view. The U.S. will have a tough job assuring Iran of its non-coercive policy if Tehran stops and rolls back its weapons program. The weaker the perception of U.S. credibility is in the Iranian calculus, the more difficult it will be to reach a future political resolution to the problem — a situation that would force the U.S. to remain ready for continued militarily engagement with Iran in periodic follow-up strikes to neutralize future attempts, while absorbing the costs of Iranian military responses to punish the U.S.

It should not be forgotten that the JCPOA is a part of a larger pathway toward rebuilding a peaceful regional security system in the Persian Gulf and the broader Middle East. This helped push forward the recent Saudi and Emirati talks with the Iranians, which are a further step toward the political resolution of other conflicts in the region. The opposite might also hold true, too. A large-scale operation against Iran’s nuclear facilities could set off a series of military tit-for-tat strikes across the region and exacerbate existing conflict zones, halting the momentum to form a peaceful regional security architecture. It could promote a renewed military approach to regional problems, which would be then adopted by other regional actors, including Iran — all of which would make it difficult for the U.S. to safely scale back its commitment or disengage from the region.

The way forward

In contrast to claims about the benefits of the threat of war for a non-proliferation strategy, a military approach to the Iran nuclear crisis has minimal non-proliferation value. Like the “maximum pressure” campaign, which posed short-term costs but failed to produce a non-proliferation value, a military strike could impose cost on Iran too, but it’s likely to fail when it comes to removing the rationale behind the Iranian nuclear program. It also has risks that might unexpectedly run out of control and increase the costs while its benefits remain disputable. The tactical ambiguities ahead of a military option and Iran’s pattern of responding to previous sabotage attempts prove the low credibility of the threat of war. Iranians know this too, and thus the threats fail to create even a meaningful level of fear that might persuade Tehran to make concessions.

Instead, political concessions should be designed on the basis of mutual interests and not mutual fears. This means a long-term resolution of international non-proliferation concerns needs to be coupled with a long-term resolution of Iranian economic and security grievances connected with the nuclear issue. The lack of an alternative option for the nuclear talks is a reality that both Washington and Tehran should eventually accept. Iran needs to accept the fact that it cannot sustain its economy forever under heavy international sanctions, especially when it can derive real economic and security benefits from the revival of the JCPOA. In the same way, the U.S. and Israel should realize that a military strike cannot resolve their non-proliferation concerns since trying to resolve a political dispute through fear is not only fragile but also a highly risky strategy. The success of the Vienna talks through painful political concessions on both sides remains the only real way forward.


Dr. Abdolrasool Divsallar is an expert on Iran’s foreign and defense policy. He co-leads the Regional Security Initiative at the Middle East Directions Programme of the Robert Schuman Centre for Advanced Studies at the European University Institute (EUI). He is also an adjunct professor at the Universita’ Cattolica in Milan. He tweets @Divsallar. The views expressed in this piece are his own.

Photo by ATTA KENARE/AFP via Getty Images