Could Trump use nuclear weapons in Iran?

IRAN

A new conflict assessment by Sibylline examines even extreme scenarios as Washington searches for an endgame in Iran

AS Operation Epic Fury enters its third week, Iran appears bruised but far from cowed.

US and Israeli strikes have battered parts of Iran’s military infrastructure, yet Tehran continues to retaliate with missile and drone attacks across the region, suggesting the conflict is unlikely to end quickly.

Attention is now turning to how the conflict might escalate if neither side backs down.

And among the scenarios now being examined is the possible use of a US tactical nuclear weapon.

In a new risk assessment of the Israel-US-Iran war, the probability of such a move is put at just 1.8% – low, but notable for a scenario that until recently would have seemed unthinkable.

“We live in a strange time where the question of whether nuclear weapons might be used in a conflict like this is actually being discussed,” says Ben Manzin, Sibylline’s lead Middle East and North Africa analyst and author of the report.

The scenario remains highly unlikely. But its inclusion reflects the volatility of the conflict – and the pressure on Washington to deliver a decisive outcome if the fighting drags on.

Manzin says the calculation behind such a move would rest on the belief that a demonstrative strike in a remote location could force Iran to back down quickly.

“If you could fire off one of these things and show that you’re willing to do it,” he says, “the argument would be that it might actually save lives by forcing them to back down.”

Yet the strategic and political consequences would be profound.

“It would kick off a new round of nuclear proliferation,” Manzin says, with countries concluding they needed their own deterrent to prevent something similar happening to them.

Even so, the nuclear scenario remains one of the least likely paths the conflict could take.

Lewis Galvin, Sibylline’s lead Americas analyst, says the probability is probably lower still.

“I do think he would care about the international message,” he says.

“And also at home there is just no way this would be sold politically or socially.”

The war itself was unpopular from the outset, he adds, including among parts of Trump’s own political base.

“His own base is against this war to begin with,” Galvin says.

The report outlines nine possible trajectories for how the war could develop over the coming month.

The most likely outcome is that US President Donald Trump declares victory and announces a unilateral ceasefire.

That scenario carries a probability of just 23.8%.

Seven of the nine scenarios examined foresee the conflict continuing or deteriorating in some form, suggesting prolonged instability remains the most likely overall outcome.

One reason is that Iran may simply refuse to stop fighting even if Washington attempts to step away.

“There is a possibility that the US stops and Iran doesn’t,” Manzin says.

Tehran could continue attacks or maintain pressure on shipping in the Strait of Hormuz to force concessions or secure guarantees against future strikes.

That dynamic creates a dilemma for Washington.

“What Trump can’t have is declaring ‘we’ve won’ and then Iran keeps firing,” Manzin says.

Military advisers may therefore push to prolong the conflict until they are confident Iran is ready to accept a halt in hostilities.

“They’ll be asking whether Iran has reached the point where it is exhausted and desperate for peace,” Manzin says.

At present, Tehran may believe it can outlast the pressure.

“They may think this is their best opportunity to put pressure on the global economic order and force concessions,” he adds.

Galvin says the war has delivered fewer strategic gains than Washington may have hoped.

Military capabilities have undoubtedly been damaged, he says, but such losses can be rebuilt.

“You can set them back,” he says. “But you can’t destroy knowledge.”

The conflict has also exposed the limits of military force in triggering regime change.

Early hopes that airstrikes might spark widespread protests inside Iran have not materialised.

“To shut down a protest, you don’t need heavy weapons,” Manzin says.

“Ten men with submachine guns can stop a crowd very quickly.”

Iran’s internal security apparatus remains intact and capable of suppressing unrest.

That reality complicates the political calculation in Washington, Galvin says.

Without the prospect of regime collapse, Trump may face growing pressure to deliver a more tangible outcome from the campaign.

“I wouldn’t quite go as far as saying it’s a watershed moment,” Galvin says. “But it is a bit of a crossroads.”

In his view, the conflict is unlikely to continue indefinitely at its current pace.

“We’re looking at either escalation or probably walking away quite soon,” he says.

If the war escalates, the United States faces a narrow range of difficult options.

One possibility would be attempting to neutralise Iran’s nuclear programme by destroying enrichment facilities or seizing stockpiles of enriched uranium. Both would be complex and dangerous operations.

Another option would be to attack Iran’s economic lifeline directly.

“If he really wanted to double down on this and try to strangle the country economically, the oil infrastructure is where you’d look,” Galvin says.

In particular, analysts point to the export hub on Kharg Island, through which roughly 90% of Iran’s crude exports pass.

Unlike hardened nuclear facilities buried deep underground, the island could theoretically be struck from the air without deploying ground forces.

“That’s probably the easiest choke point they could go for,” Galvin says.

“But the market impact would be beyond turbulent. None of these options are easy.”

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