On 12 April US and Iranian teams will meet in Oman to find a way out of the impasse on Iran’s nuclear programme.
In 2015 a deal was agreed after some prolonged and painstaking negotiations led by the Obama administration, supported by the Europeans, Russians and Chinese. This was the Joint Comprehensive Plan of Action (JCPOA). Iran agreed to cut back on its uranium enrichment programme in return for sanctions relief. Trump abandoned the JCPOA in 2018 claiming that Obama’s deal wasn’t good enough and that he would get a better one by imposing “maximum pressure”.
As was predicted in 2018, the Iranian response to the US campaign of maximum pressure was not to offer the Americans more but instead to press ahead with enriching uranium to the point where they are now close to having enough to build some nuclear weapons should they choose to do so. Time is therefore running out for a deal.
In February the International Atomic Energy Agency (IAEA) reported that Iran had stockpiled almost 275 kilograms of 60 per cent enriched uranium, which would not take much extra enrichment to get to 90 per cent, when it would be weapons-grade. That would be enough for six bombs. Under the JCPOA, the objective was to ensure that Iran was always at least a year away from being able to use its highly enriched uranium (HEU) to manufacture weapons. Estimates vary for how long this would take, but they are generally less than a year.
Talks to revive the JCPOA continued during the Biden administration but the conditions were hardly propitious, as Israel battled Iran’s “axis of resistance”. Only desultory progress was made. At the start of his second term Trump offered to talk, while also increasing economic sanctions on Iran and threatening military action. On 30 March, Trump said that if Tehran doesn’t agree to a deal “there will be bombing and it will be bombing the likes of which they have never seen before”. This led to Ayatollah Ali Khamenei, Iran’s supreme leader, ruling that there could not be direct talks with the Americans. Iran, he vowed, would not be cowed by American threats. Nor, on the basis of past experience, could he trust Trump to stick to an agreement.
But Iran is not in great shape to resist. Its economy is a complete mess, partly because of sanctions but also because of years of chronic mismanagement and corruption. The clerical regime is deeply unpopular and stays in power largely through repressive measures. Its “axis of resistance”, based on a coalition of sponsored militias with a shared hatred of Israel – including Hamas in Gaza and Hezbollah in Lebanon – has been shattered by Israeli action. The Houthis in Yemen are still active, though they have recently been struck regularly by the Americans (as featured in the leaked Signal chat). Syria’s Iranian-backed Assad regime collapsed in December. A few weeks before that, Israeli strikes had weakened Iranian air defences and reportedly struck one nuclear facility, reminding Iranians of their vulnerability.
There has been a build-up of US forces in threatening positions, including half a dozen B-2 bombers transferred to the Diego Garcia base in the Indian Ocean. Two carriers – the USS Harry Truman and USS Carl Vinson – are in the vicinity. Air-defence batteries have been moved to Gulf states. Some of this may be related to the ongoing fight with the Houthis but it may also have a coming confrontation with Iran in mind. All this may have persuaded Khamenei that, for now, discretion is the better part of valour.
There is uncertainty about the proposed nature of the talks. Trump said that there would be a “very big meeting” and that the talks would be “direct”. The Iranians have said that they would be “indirect” though “high-level”. The two key players are Steve Witkoff, Trump’s favourite fixer, and the Iranian foreign minister, Abbas Araghchi. “Indirect” means somebody will pass messages between them. Perhaps at some point they may find it useful to talk face to face.
Araghchi has stated that the first agreement needs to be that there can be no “military option”, let alone a “military solution”. Trump won’t say that. His position is that “Iran cannot have a nuclear weapon, and if the talks aren’t successful, I actually think it’ll be a very bad day for Iran”.
Trump’s implication is that what cannot be achieved by diplomacy could still be achieved by military action. Before returning to diplomacy, I’ll consider the military option, and how Iran might respond.
What will be the targets for any attack, whether conducted by the US alone or with Israel? This issue is sufficiently discussed in the unclassified literature to allow us to identify sites that are likely to be struck, though not how easy it will be to destroy them. We can assume, from events last year, that US and Israeli intelligence are reasonably well informed on the state of the Iranian programme and how it is organised.
The extent of Iran’s nuclear programme was revealed at the start of this century. Since then, Tehran has faced the ever-present possibility of military action designed to eliminate this capability, although the preferred Western approach has been a combination of economic coercion and the promise of negotiations. The programme has also been the subject of cyberattacks and the assassination of key personnel, but these have caused no more than delays. Because of the constant threat of military action in the background. Iran has paid careful attention to the visibility and vulnerability of the key facilities during their construction. Many are well dispersed with some placed in mountains or hidden underground.
There are many potential targets. This list contains 42 directly related to the nuclear fuel cycle, from extraction of uranium ore to research to nuclear reactors. These are known to the IAEA. There are another eight undeclared sites, more related to weapons production, including stored nuclear material and research on explosives. There may be others that have remained secret or at least obscure.
The facilities most regularly identified as providing the key targets are:
– Natanz Fuel Enrichment Plant (FEP), which is large and underground. There is also a Pilot Fuel Enrichment Plant (PFEP), which is buried about three storeys into the desert.
– Fordow Fuel Enrichment Plant (FFEP). This is built deep into a mountain. Under the 2015 agreement uranium enrichment was supposed to cease. But after the US withdrawal Iran resumed enrichment activities at the site, which has been used to produce Iran’s stockpile of HEU.
– A centrifuge manufacturing site at an underground facility near Natanz.
– A “nuclear weapons research facility” at the Parchin military complex was reportedly destroyed during Israeli strikes last October, and similar sites would be targeted in any future attacks.
Destroying the most protected sites would not be simple, as Darya Dolzikova and Justin Bronk explain in a recent paper for the Royal United Services Institute (Rusi). Most Iranian facilities are likely to be covered by layers of reinforced high-density concrete, rock, packed earth and other materials, which may be 80-100 metres thick. Assuming US weapons can penetrate these layers and cause an explosion, the effects will depend on whether the facility has narrow shafts and thick blast doors, which will limit the impact, or else, and unlikely, is simply a large cavern with a single exit and entry point.
Dolzikova and Bronk point out that many weapons may be required for each protected facility. Several weapons may need to be detonated into the same crater to “burrow” down into the facility to the point where it can be destroyed. Even with the most powerful “bunker-busting” bombs there will need to be “multiple impacts at the same aiming point to have a good chance of penetrating the facility”. These sites may have more vulnerable points, for example entry and exit tunnels, but good intelligence would be required for them to be targeted effectively.
Before the targets can be reached the attacking force would need to be able to deal with air defences. These did not seem to trouble Israel too much in its October 2024 strikes and would be even less likely to trouble the US Air Force. But around the key sites there will be intensive defences, not all of which may be known to US intelligence, especially as some systems will be mobile. Even with good intelligence many aircraft would still be needed to suppress the defences as well as attack the targets. It would be prudent to assume some weapons might be intercepted before they reach their targets. And there are reports of Iran recently strengthening air defences, constructing new radars and conducting air-defence exercises around nuclear facilities.
A serious campaign against the Iranian nuclear programme would therefore need to be substantial and ongoing. Noting that Israel used over 100 jets in its October strikes on Iran, Mark Urban reports “estimates of the number of aircraft required to hit Iran’s enrichment plants and other key targets in the 2-300 bracket”. In his most recent comments, after confirming that the military option was there if needed, Trump appeared to say that Israel will take the lead in an attack: “Israel will obviously be very much involved in that – it’ll be the leader of that.” Then, as if realising he’d said more than he should, he added: “Nobody leads us. We do what we want to do.”
Could Israel do the job on its own? One study on Israeli options suggests not. The US has denied them the biggest bunker-busting bombs (which would need to be much bigger than those used to destroy the Beirut compound of Hezbollah’s Hassan Nasrallah last September). They also lack the refuelling capability to enable their aircraft to get close enough. Others are less sure, if for no other reason than this mission has been a high priority for the Israeli Defence Forces (IDF) for some time, and they are capable of developing surprising capabilities (as we saw with the pager attacks on Hezbollah’s leadership). Nonetheless, it would certainly be difficult to conduct an operation without US support, and Trump has now implied that an Israeli operation facilitated by the US, is the preferred option. This raises larger issues, because one led by Israel would at least take longer and risk being less effective, leaving the US still associated with an operation that had not quite succeeded.
A substantial attack would likely set back Iran’s ability to build a bomb significantly though probably not permanently. Much will depend on the extent of any damage inflicted. The Iranians will try to recover what they can as soon as possible. The first round of strikes may, therefore, not be the end of the matter. Regular strikes may be necessary to prevent the sites being returned to their previous state. Iran’s nuclear capability resides in its scientific knowledge as much as its facilities. That would remain even after strikes.
Should an attack be launched, what would be the Iranian response?
During the period of “maximum pressure” in Trump’s first term, which included the assassination of the Iranian militia leader Qasem Soleimani in January 2020, Iran took its own military action. This included sabotaging tankers in the Gulf, missile and drone attacks on Saudi Arabia’s oil infrastructure, and firing missiles at an Iraqi base hosting US soldiers.
Two things have changed since then. First, Iran and the Gulf states, including the Saudis, have worked to mend relations. Arab governments give every indication of wishing to keep clear of another round of fighting between the US/Israel and Iran. Second, given the weakened state of Hamas and Hezbollah, it has fewer proxies available to unleash attacks against Israel and US assets in the region. There are still the Houthis in Yemen as well as militias in Iraq. The Houthis have been targeted on an almost daily basis since 15 March. They haven’t gone away and have shown great resilience. The Iraqi groups also still remain, although recent reports suggest that the leaders of Kata’ib Hezbollah and other militias have decided that they would rather not get into a direct fight with the US, and are prepared to disarm. It seems unlikely that these potential forms of retaliation will have much of an effect on US calculations. Iranian sources have suggested that the US base on Diego Garcia could be struck with a combination of cruise and ballistic missiles. This base could be one of the launch pads for any US attack. But it is also well defended and would be at the edge of Iranian range (which would mean that only relatively small warheads could be carried).
While Iranian leaders may feel that as a matter of honour they need to hit back in some way, the most significant response would be to move as quickly as possible to recover the programme and start building bombs. This will obviously require that sufficient capabilities have survived the attack. Constant threats against Iran, and occasional strikes, may well convince Tehran that its own deterrent is essential. There is currently a fatwa in place, issued by Khamenei in 2003, that prohibits Iran from the production and use of nuclear weapons. How much this is an actual constraint is hard to know but if it were lifted that would be a clear signal of Iranian intent. They are also signed up to the Nuclear Non-Proliferation Treaty and have in the past threatened to withdraw.
Inevitably, the many uncertainties surrounding the use of military force argue to place more weight on negotiations. This case has been set out recently by Richard Nephew, who worked on this issue for the Biden administration: He wrote:
“There are still many good reasons to not bomb Iran. Striking the country would inject more chaos and instability into the Middle East. It would consume substantial American resources at a time when Washington wants to focus on other regions. It could undermine US credibility if the attacks don’t succeed. And the odds of failure are high: even the most accurate strikes might only delay Iranian nuclearisation. The best, most durable solution to the issue remains a diplomatic agreement.”
The Europeans have not stopped talking to Iran, but they are on their own collision course. With a mechanism known as “snapback”, Britain, France and Germany have warned Tehran that in the absence of a new nuclear deal by the summer, they will renew sanctions against more than 300 Iranian entities. Under the 2015 JCPOA Security Council resolution, snapback is automatic if requested by any of these three states before 18 October, when the original agreement largely expires. There can be no Chinese or Russian veto.
The US-Iranian talks might build on these conversations. But if they are to make progress a basic decision on objectives will need to be made. Up to now, the position of the administration has been that the nuclear programme must be dismantled completely. It has gone further, insisting that Iran’s long-range ballistic missiles must go, along with its regional “terrorist network”. Benjamin Netanyahu was sitting beside Trump as he spoke of talks and did not look overjoyed when they were announced. He has long hoped that the US could be persuaded to strike hard against the Iranian programme. He welcomed the talks but only if they led to a Libyan-type deal, as agreed in 2003, which would mean complete disarmament. This sets a very high and improbable bar for success.
Trump may prefer a lower bar. If there is to be any chance of the talks succeeding he needs scaled-back objectives. Witkoff has suggested a better “verification programme so that nobody worries about weaponisation” would be sufficient. That would certainly be more realistic. Araghchi insists that Iran had not violated its commitment not to seek nuclear weapons, but claims to be ready to address “possible concerns about our nuclear programme”.
“We are willing to clarify our peaceful intent and take the necessary measures to allay any possible concern. For its part, the US can show that it is serious about diplomacy by showing that it will stick to any deal it makes. If we are shown respect, we will reciprocate it.”
In the end Trump may be happy for a deal that takes an issue off his “to-do” list for now. But there will still be demands from Tehran for sanctions relief which Trump might find harder to concede.
There is also a view, encouraged by some opposition groups in Iran, that there should be no deal because that would involve easing the regime’s economic predicament. On this argument the best thing to do is to wait for and encourage the collapse of the clerical regime and then do the deals. But while its foundations appear fragile, it is hard to be confident of its imminent demise. Moreover, the regime could use the opportunity of a confrontation with the US to crack down on opposition groups.
There are suggestions that Trump has given diplomacy two months. With the October JCPOA deadline looming it is difficult to let the issue drift, even if neither the diplomatic nor the military options appear promising. If the talks on 12 April do not lead to a more direct and substantive negotiation, Trump may still prefer to see if intense economic pressure will do the trick rather than take the risk of getting into a long and uncertain military operation. But with Iran so close to a weapon, the pressure for this to be resolved soon, one way or the other, is intense.
Lawrence Freedman is a regular contributor to the New Statesman. This piece originally ran on his Substack “Comment is Freed”.
[See also: To catch a strongman]
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