RUSI Experts React to US Strikes on Iran's Nuclear Facilities

'Following the US surgical strikes on three Iranian nuclear facilities, the concern is what form the Iranian reaction will take. Iran’s credibility, internally and externally, has received an unprecedented blow, as it ultimately failed to shield its coveted nuclear programme. There is a tenuous chance that the risk of escalation may be contained—provided Washington signals strongly that its operation was narrowly focused on curbing Iran’s nuclear capabilities rather than a grand strategy to pursue regime change.'

'Iran had vowed to retaliate harshly against US interests in the Middle East if it attacked Iranian nuclear sites. Now that the strikes have come, Tehran faces a stark dilemma: retaliate and risk a wider war or pause to consolidate at home.'

'De-escalation may allow the regime to focus inwards to deter political instability, reinforce elite command and control, and manage the political fallout from ten days of war with Israel. But inaction carries its own cost—undermining Tehran’s credibility after years of vows to protect its nuclear program at all costs. Iran’s options are both limited and incredibly risky.'

'Mobilising proxies in Iraq or Yemen could invite punishing US reprisals, particularly if American forces suffer casualties. More perilous still would be an attempt to disrupt or shut the Strait of Hormuz—an act that could trigger global economic shockwaves and runs counter to Iran's own interests. Tehran’s next move may determine whether this war expands—or ends in uneasy, albeit possibly temporary, restraint.'

'The deeper question is whether Iran will rush to rebuild, believing deterrence lies in speed? This has been the long-feared scenario. Or will the strikes serve as a sobering lesson—that any move toward weaponisation invites direct attacks on the Iranian homeland? Last night’s assault may have disrupted the program’s momentum, but it has not extinguished the strategic dilemma at its core. There is a gap between Iran's nuclear intent and capability—it is yet unclear how far last night’s US strikes went in widening this gap.'

'To reduce the risk of further escalation across the region, Israel will have to determine now at what point it will suspend its military strikes against Iran. While the full extent of the damage to the three sites, Fordo, Natanz, Isfahan, is yet to be determined, the US strikes achieved what Israeli policymakers have long sought: a significant setback to Iran’s nuclear program and a demonstration that the US is willing to act.'

'But continued Israeli military action—especially if it targets regime infrastructure—risks reinforcing Tehran’s belief that the endgame is not deterrence, but regime change.'

'This could entrench Iran’s resolve and push the conflict into a far more dangerous phase. What bears close scrutiny now is the internal cohesion of the Islamic Revolutionary Guard Corps (IRGC) and the decision-making dynamics around Supreme Leader Ali Khamenei. These will shape whether Iran opts for escalation, restraint, or something more unpredictable.'

Comments by Dr Burcu Ozcelik, Senior Research Fellow, Middle East Security

'The nature of the facility at Fordow – under a mountain – means that the success of the operation is not immediately apparent. Imagery can’t show much about the damage down at the centrifuge enrichment hall, so the US and Israel will be relying heavily on intelligence from inside the Iranian system. Reporting that strikes were also launched on Esfahan and Natanz (including Massive Ordnance Penetrators at the latter) are consistent with an attempt to eliminate uranium enrichment facilities. UK ministers have said that the UK was not involved, and publicly available data is consistent with this in terms of the ability of B-2 bombers able to fly from the US mainland being refuelled in the air.'

'If the Iranians choose a broader military response against US forces, there are targets across the Middle East, especially in Qatar, Bahrain, Iraq and Saudi Arabia, but all would risk widening the conflict at a time of extreme vulnerability for the Iranian regime and some US forces already appear to have been dispersed from locations such as Qatar. Their ballistic missile forces have been firing salvoes at Israel of decreasing size, though they have not yet used much, if any, of their cruise missile stockpiles. The UK is present at many of these locations, and would need protection from ballistic missiles provided by US Patriot batteries, while UK Typhoon jets at Cyprus could provide some air defences against drones and cruise missiles. It is likely that Israeli strikes will continue, given their stated intent to cause wider damage to the Iranian military beyond the nuclear programme.'

Comments by Matthew Savill, Director of Military Sciences

'The precise details of any further damage that the latest US strikes have caused to Iran’s nuclear sites is unclear. However, the fundamental reality remains that military action alone can only roll back the programme by degrees, not eliminate it fully. There are thus a number of key questions to consider: how much damage to the programme is enough for Israel and the US to feel that they have reduced the programme sufficiently for the time being? What effect have the strikes had on Iran’s resolve to advance and potentially even weaponise the programme? And what are Israeli and US plans moving forward to manage what remains a persistent - albeit degraded - threat?'

'If Fordow was indeed seriously damaged in the latest round of strikes - which remains unclear - that would certainly be a significant blow to Iran’s ability to produce fissile material for a nuclear weapon. The Fordow Fuel Enrichment Plant (FFEP) has been key to Iran’s nuclear programme, enriching uranium to 60%, more efficiently than at Natanz. Further attacks on Natanz and Isfahan - depending on the nature and extent of the damage - would have also helped set the programme back further.'

'However, questions remain as to where Iran may be storing its already enriched stocks of HEU - as these will have almost certainly been moved to hardened and undisclosed locations, out of the way of potential Israeli or US strikes. It is also unclear what secret facilities may exist inside Iran that Tehran could use for continued centrifuge production, enrichment and weapons-relevant activities. There is also currently no information on the state of the facility at Kolang Gaz La, not far from Natanz, which has been under construction inside a mountainside - reportedly deeper than the FFEP.'

'Besides the actual physical capabilities, Iran retains extensive expertise that will allow it to eventually reconstitute what aspects of the programme have been damaged or destroyed. The Iranian nuclear programme is decades old and draws on extensive Iranian indigenous expertise. The physical elimination of the programme’s infrastructure - and even the assassination of Iranian scientists - will not be sufficient to destroy the latent knowledge that exists in the country.'

'Finally, while military strikes and assassinations can degrade the technical nuclear capabilities and expertise that underpin the nuclear programme, they risk having the exact opposite effect on Iran’s threat perceptions and calculations. Deterring US military presence and action in the region - let alone against its own territory - has long been assumed by analysts to be one of the drivers of Iranian advances on its nuclear programme. The latest round of strikes and the fact that the US has - for the first time - carried out direct attacks on Iranian territory may very well result in a decision in Tehran that the only option they have for an effective nuclear deterrent is to produce a nuclear weapons capability.'

'It is as yet unclear what Iran’s response to the latest round of strikes may be. Retaliatory strikes against US assets in the region is one possibility. However, the escalatory risks that they presents could help to mitigate that risk somewhat. An Iranian announcement of withdrawal from the Nuclear Non-Proliferation Treaty is also now a real possibility. The NPT allows member states to withdraw “if it decides that extraordinary events, related to the subject matter of this treaty, have jeopardized the supreme interests of its country.” The events of the last week could arguably give Tehran the justification it needs to that end. A withdrawal from the NPT (which would have to follow a three-month notice period) would likely see the international community lose all visibility of the Iranian nuclear programme and could - long-term - become a catalyst for broader proliferation in the region.'

Comments by Darya Dolzikova​, Senior Research Fellow, Proliferation and Nuclear Policy