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Analysis Series
Analysis/0066/August/2026/London-Dialogue. 21 August 2026
Author: Dr. Hichem Karoui
The fundamental problem facing the Trump administration is that it waged two consecutive wars with the clear goal of overthrowing the Islamic Republic of Iran and failed. Today, this administration finds itself under immense pressure, which has led it to flounder without a solution: after accepting the memorandum of understanding with Iran (which appeared to be an acceptance of Iran’s terms), the U.S. president backtracked and returned to a rhetoric of threats, intimidation, and the blockade of the Strait of Hormuz. If he negotiates without achieving a clear military victory over Iran, he will appear to have lost face, something completely at odds with what he came to do, according to the political rhetoric he promoted about “Making America Great Again”. Faced with this impasse, observers are asking, is the only option left for Trump to “put Iran in its place” to launch a tactical nuclear strike, or strikes, against it?
Overview and Strategic Context
The question of a US tactical nuclear strike on Iran must be situated within the actual, and heavily contested, trajectory of the 2025–2026 conflict. In June 2025, Operation Midnight Hammer saw US B-2 Spirit bombers drop more than a dozen 30,000-pound GBU-57 Massive Ordnance Penetrator bunker-buster bombs on the Fordow and Natanz enrichment sites, which President Trump and the Pentagon publicly described as “historically successful” and having “obliterated” Iran’s nuclear programme. That framing was disputed almost immediately. A leaked Defence Intelligence Agency battle-damage assessment concluded the strikes did not destroy the programme’s core components, that centrifuges and much of the enriched uranium stockpile were “largely intact”, and that Iran’s timeline had been set back by a matter of months rather than permanently disabled. The White House response was to attack the leak’s source rather than rebut its substance, with the press secretary calling the leaker a “low-level loser”, while independent nuclear analysts such as Jeffrey Lewis, reviewing commercial satellite imagery, likewise expressed doubt that Fordow’s tunnels had fully collapsed.
CSIS’s own tracking of the episode is titled “Disruption or Dismantlement” precisely because Israeli, US, and IAEA assessments diverged. Israeli officials described Natanz’s above-ground facilities as “completely destroyed” but expressed uncertainty about whether Fordow’s underground infrastructure had fully collapsed, and IAEA Director General Rafael Grossi called it “extremely unlikely” that centrifuges survived while stopping short of confirming total destruction. By late 2025, ISIS satellite monitoring found the three main sites “largely destroyed” with minimal rebuilding activity, a picture more consistent with severe degradation than either the administration’s claim of total obliteration or the DIA’s initial scepticism. The honest analytical position is that the strikes caused real, significant damage but did not achieve the clean, total destruction claimed publicly and that competing intelligence agencies, not just political spin, genuinely disagreed on the scope.
Would a Nuclear Strike Even Be “Necessary” or Feasible?
Defence analysts and nonproliferation experts are near-unanimous that no coherent military rationale exists for a nuclear strike on Iran. CSIS laid out five options for reaching a hardened site like Fordow: the GBU-57 penetrator, sustained Israeli conventional strikes, sabotage, ground commando raids, and nuclear weapons and concluded that repeated conventional strikes were the operative path without resort to nuclear weapons. Public commentary echoes this: there are no valid reasons to use nuclear weapons against Iran, as there are no targets that would justify such an action, since Iran’s nuclear infrastructure is dispersed and already vulnerable to advanced conventional penetrators.
This reflects a broader nuclear taboo, an international norm against the first use of nuclear weapons rooted in revulsion at their indiscriminate effects, reinforced legally by the 2021 Treaty on the Prohibition of Nuclear Weapons. Scholarship by Scott Sagan and Benjamin Valentino has cautioned that this taboo may be “weaker than commonly assumed” under extreme conditions, but even that research does not identify Iran’s nuclear programme as a plausible trigger for US nuclear first use, given the availability of conventional alternatives.
Hypothetical Targets: Tehran, Nuclear Sites, or Leadership
- Fordow Fuel Enrichment Plant, buried roughly 80–90 metres under a mountain near Qom.
- Natanz enrichment complex, Iran’s largest facility.
- Esfahan nuclear technology complex, whose deep tunnel systems remain of uncertain integrity.
- Taleghan 2, a weaponisation-linked site rebuilt since being destroyed in 2024.
A strike aimed at decapitating the regime, hitting IRGC command nodes, missile depots, or senior leadership, potentially including Tehran, represents a distinct targeting logic from one aimed at nuclear infrastructure. Nothing in open-source reporting suggests US planning has contemplated a nuclear detonation over Tehran itself; all serious targeting scenarios discussed by analysts concern remote, hardened military and nuclear sites rather than the capital’s civilian core.
Radiological and Humanitarian Consequences
Even limited nuclear use against buried facilities would produce consequences qualitatively different from the conventional strikes already conducted. Health physics experts assessing the conventional GBU-57 strikes noted that uranium hexafluoride released underground would likely stay largely confined near the site, with IAEA data suggesting radiation levels outside Natanz “remained unchanged” after conventional strikes. A nuclear detonation, by contrast, would introduce fission products, blast overpressure, and thermal effects far beyond anything associated with conventional penetrators, alongside the political and normative earthquake of the first use of a nuclear weapon in war since 1945.
Regime Survival: Would a Strike Topple Tehran?
The regime has already survived the 2025 and 2026 conventional campaigns, including a reported leadership transition, while the IRGC retained control and suppressed subsequent protests. The Stimson Center warns that if collapse does occur, “it will do so unevenly and violently”, resembling Syria’s or Libya’s fragmentation but on a far larger scale.
Iran’s Retaliatory Capabilities
Even after strikes degraded roughly one-third of Iran’s missile launchers, Iran retained a substantial retaliatory arsenal, with estimates suggesting it still possessed approximately 2,000 heavy ballistic missiles thanks to an industrial base producing several hundred monthly and dispersed underground “missile cities”. Demonstrated tools include:
- Direct ballistic missile strikes on US bases in Jordan, Saudi Arabia, and elsewhere.
- Strikes on civilian infrastructure, including a power and desalination facility in Kuwait.
- Manoeuvrable re-entry vehicles designed to defeat US missile defences.
- Swarm drone and missile tactics against ship defences in the Gulf.
- Mining or threatened closure of the Strait of Hormuz, through which roughly one-fifth of global oil transits and where Iran holds an estimated 6,000 naval mines.
- Cyber operations are expected to become more “decentralised” and harder to control under any regime-collapse scenario.
Does Iran Possess Weapons of Mass Destruction?
According to current IAEA verification reporting, Iran does not presently possess a nuclear weapon. The most recent IAEA assessment found no evidence of a structured weaponisation programme, though Iran’s uranium enriched to 60% purity reportedly exceeded 408 kilograms as of May 2025. ISIS’s probabilistic model places the likelihood the regime decides to build a weapon at 40–50%. On chemical and biological weapons, the picture is starker: Iran is a state party to the CWC and BWC, but Western assessments have long described it as having had “the most active chemical warfare programme in the developing world” historically, with a mature dual-use biotech base capable of producing agents like anthrax.
Retaliation Targets: Who Would Iran Strike?
- US military bases across the Gulf, including Al Udeid (Qatar), Al Dhafra (UAE), and Kuwait facilities.
- Israeli territory directly, via missile and drone salvos.
- Gulf civilian and energy infrastructure, even in states hosting no attacking aircraft.
- Maritime shipping through the Strait of Hormuz.
Asymmetric, proxy, and cyber operations region-wide
Gulf and Regional Consequences
The Gulf Cooperation Council states have already borne heavy, demonstrable costs from the conventional phase of this conflict, not minor or contained ones, and a nuclear escalation would sharply compound them. Iran has repeatedly struck US and allied bases across the region, including Al Udeid, Al Dhafra, Ali Al Salem in Kuwait, the US Fifth Fleet HQ in Bahrain, and THAAD radar installations in Jordan, the UAE, and Saudi Arabia, destroying at least one radar system outright. Satellite-imagery analysis by the Washington Post documented damage to at least 228 structures or pieces of equipment across Gulf bases, far more than the Trump administration has admitted to, with several bases rendered “all but uninhabitable” and roughly 800 million dollars in base damage within the war’s first two weeks alone. Reporting into July 2026 confirmed continuing Iranian strikes at bases in Jordan, Bahrain, and Qatar even as Trump publicly claimed the US had “demolished” Iran’s military; an FPRI analyst noted the US had failed to attrit Iranian forces enough to stop the attacks. Jordan alone intercepted 49 drones and missiles in a single Iranian salvo, and Iran struck a base and command centre in Jordan again as recently as late July 2026.
At least 28 people were killed across the six GCC states from Iranian strikes since the campaign began, despite GCC states insisting no attacks against Iran originated from their territory. This exposed a structural vulnerability: hosting 40,000–50,000 US troops across at least 19 regional bases has not shielded Gulf states from retaliation and has instead made them targets, per Lancaster University’s Simon Mabon, prompting warnings that “the U.S. security umbrella is ineffective at best and moribund at worst”.
Israel’s Position
Israel conducted its own 12-day war against Iran’s nuclear programme in June 2025 and joined the US in the larger 2026 campaign, driven by the assessment that a nuclear-armed Iran would pose “a major, perhaps existential threat”. A nuclear strike by the US would almost certainly draw immediate massive Iranian missile retaliation against Israel, consistent with the roughly 35 ballistic missiles Iran launched in the first wave of retaliation earlier in this conflict.
Synthesis
Across every category examined, expert consensus converges on a sobering, and less flattering, picture for Washington than official statements suggest. The conventional campaign did not cleanly solve the nuclear problem: independent and even internal US intelligence assessments found Iran’s core nuclear capability degraded but not destroyed, with enriched uranium stockpiles largely unaccounted for and centrifuge know-how intact. Nor has the conventional war demonstrated dominance sufficient to suggest a nuclear strike would be low-risk. Iran has sustained repeated, damaging strikes on US and allied bases across Jordan, Bahrain, Qatar, Kuwait, and the UAE for over a year, exposing the limits of US missile defence and regional deterrence rather than confirming it. RAND’s analysis of a hypothetical nuclear-armed Iran concludes that nuclear weapons are unlikely to be useful even for Iran itself in coercing Gulf states.
Dr Hichem Karoui
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