After Donald Trump’s humiliation in the midterm elections, a key question for many is whether he will resume military strikes against Iran – and if so, how hard.

On the night of the Republican Party’s dramatic defeat, the US President admitted that his war had damaged his party, but hinted that further strikes could be on the horizon. “We have to do something large,” he said, adding that it could involve a “heavy hit”.

This came days after he warned that the US was “going to have to give them the hammer”, before telling the shortly after that he had no immediate plan to strike Iran.

Trump has said that the war could resume after the midterms, while also suggesting a peace deal is possible. It remains unclear what the reality will be. US presidents who suffer midterm defeats often turn to foreign policy.

However, following the results, JD Vance, the Vice President, went public with his condemnation of the war, arguing that voters had soured on Republicans as a direct result of the military action, which led to a huge rise in fuel prices, adding to the cost of living crisis.

In his first speech after the midterms defeat, Trump insisted he had no other choice but to launch the conflict, adding: “You can’t let Iran have a nuclear weapon.”

Amid fears that he will want to reassert his authority as President, Washington insiders have even raised the alarm over the unthinkable: that Trump could use a nuclear weapon.

Tucker Carlson, a former Fox News host and close ally of the President before a bitter split, said that the Trump administration “may be within days of launching a nuclear strike on Iran”, citing “informed” sources. Carlson has become a fringe figure since leaving Fox News – albeit with a huge following – but others have echoed his concerns.

Trump biographer David Cay Johnston told The i Paper that his subject’s erratic behaviour led him to believe: “It is not beyond reason that he will toy with the idea of actually using nuclear weapons.” 

Jon Wolfsthal, the former top US official for nuclear weapons and proliferation, said in April that Trump’s apocalyptic threats against Iran had raised concern among “very serious, sober” nuclear experts – noting that a US president has total authority over use of nuclear weapons.  

Trump’s previous statements on Iran have at times been highly aggressive, including a social media post from April that stated “a whole civilisation will die tonight, never to be brought back again”. Some took the message as a veiled nuclear threat.

His unpredictability – and the costly stalemate in the war – have fuelled fears of escalation. But many nuclear specialists and ex-officials say they are confident Trump will not become the first leader to shatter a taboo that has held since 1945, when Harry S Truman authorised the use of atomic bombs against Japan.

Iran’s nuclear capabilities

The Trump administration has refused to rule out the use of “tactical” nuclear weapons to attack Iran’s buried nuclear sites, telling Fox News that no options were “off the table” prior to a strike on the country’s Fordow facility in 2025. 

The President has suggested that Iran’s so-called Pickaxe Mountain could be a target following reports that the nation is using the site for clandestine nuclear activities. But military experts believe it could survive an attack from the most powerful conventional munitions in the US arsenal – including the 10-tonne MOAB – the “Mother Of All Bombs” – that the White House is reportedly considering.  

“The issues with targeting this facility are substantial,” Mick Mulroy, the US Defence Department’s top Middle East official during Trump’s first term, told The i Paper. “The mountain itself is composed of extraordinarily hard granite. And the layout of the facility itself is not known.  

“Our largest massive ordnance penetrator munitions may not be able to destroy the facility 100 metres below. And there is the problem of confirming whether the facility is destroyed.”

Specialists at military news outlet suggest the only sure way to destroy the facility would be via a nuclear weapon, specifically the B61 bomb, which could deliver a 400-kiloton blast.

Pressure to bring down the regime

The US military has carried out “defensive” air strikes on southern Iran this week, as low-level hostilities continue with little prospect of a resolution. Trump said on Tuesday that overnight attacks on Iran were minor. “It wasn’t war,” he told Fox News. “I’m not looking to kill lots of people, but if we have to, we’ll have to. And we’re very strong right now.”

Tehran is demanding reparations for war damage, and recognition of its control over the Strait of Hormuz, among other conditions for a peace deal, which the US has rejected. The White House insists Iran must give up its nuclear fuel and future enrichment, which Tehran will not consider. 

The stalemate has increased the chances of a return to a war of even greater intensity. Israel’s Prime Minister Benjamin Netanyahu is pressing for a war to bring down the Iranian regime. White House officials say civilian infrastructure such as power plants could be targeted.   

Mulroy added that he expects military action to resume if there is no imminent peace deal, with “economic targets” in the US crosshairs.

Why the nuclear taboo should hold 

While Trump has cycled between threats to Iran and predictions for an imminent deal, he has been consistent in ruling out a nuclear attack. “We don’t need it,” he said in April. “A nuclear weapon should never be allowed to be used by anybody.”

Trump reiterated the position in August, saying: “They’re totally defeated militarily, so I defeat them, and now I should use a nuclear weapon on top of them?”

Pavel Podvig, a senior researcher in weapons of mass destruction at the UN Institute for Disarmament Research (Unidir), suggested that such a momentous move as a nuclear strike would require preparations. 

“At the very least, I would expect that any consideration of nuclear use would be preceded by a change in rhetoric,” he said. “We haven’t seen this, so I read it as a sign that nothing nuclear is being considered.”

The nuclear taboo works partly by setting the “initial conditions” of a conflict, Podvig said, and “the default option is not to use nuclear weapons”.

Mulroy also believes Trump would stop short of a nuclear attack. “The idea that the US could use a lower-yield, ‘tactical’ nuclear weapon would be a massive escalation, and cross a threshold that would have major consequences and potentially spread radioactive material throughout the region,” he said.  

As Carlson noted, America’s use of atomic weapons would set a precedent that could lead to nations such as Russia or North Korea following suit, which could serve as a deterrent to Trump. 

Hans Kristensen, director of the Nuclear Information Project at the Federation of American Scientists, told : “There is nothing at all in Iran that justifies breaking the 81-year absence of nuclear weapons use. It would be a violation of the international Laws of War, have devastating consequences for US foreign policy and the efforts to prevent proliferation and the use of nuclear weapons.

“It would be the kind of act where one would hope the people in the nuclear chain of command would refuse to carry out the President’s order.”