How does the Iran war end?

The United States went to war with Iran for reasons that remain unclear. 

At various points, the president and his allies have argued that this was a war of preemptive self-defense, an effort to prevent Iran from rebuilding its nuclear program, and even an attempt at regime change. The justification seems to change based on who is speaking and who they are speaking to, making it difficult to divine what the president seeks to get out of all of this — or if he even has a coherent end goal in mind.

Given this mess, is there any way to predict how it might end?

To find out, we spoke with eight leading experts on Iran, the Middle East, and US military policy. The clear consensus is that the best-case scenario offered by the Trump administration — that US bombs inspire Iranian people to rise up and topple the regime — is extremely unlikely. Nothing like that has happened in the history of air warfare, and Iran experts do not think this will be the exception to the rule.

“It’s a fantasy to think that aerial bombardment is going to open such a gap that there will be a new regime,” says Hussein Banai, a professor at the University of Indiana-Bloomington who studies Iranian politics.

If this analysis is right, there are two broad categories: some kind of settlement, where the US stops short of its maximalist aims, or escalation.

Of the two, the former is generally seen as more likely. A settlement could follow something like the “Venezuela model,” where President Donald Trump receives some policy concessions in exchange for leaving the regime broadly intact, or the US simply declaring victory based on some lesser accomplishment (say, doing more damage to nuclear program sites).

But either way, the war ends without the regime change that many in the White House (and Israel) desperately want.

In the second scenario, the US gets dragged deeper into a conflict — moving beyond bombing into some kind of ground campaign to topple the regime. This is widely seen as unlikely; most observers believe Trump is eager to avoid his presidency becoming defined by an Iraq-style disaster. 

But unlikely is not impossible. And given the opaque goals of this war, and the nature of the many stakeholders involved, the range of possible outcomes is wider than perhaps anyone is able to predict — including the top decision-makers in Washington.

“No world leader has ever launched a military operation expecting a quagmire,” says Caitlin Talmadge, a political scientist who studies war at MIT. “What you’ve essentially heard our leaders saying is denying that these risks exist, and that they’re effectively in control of the tempo and outcomes — and that’s antithetical to everything we know about how war works.”

Why bombing is unlikely to change the regime 

Trump launched this war, at least in part, because his prior attacks on Iran went better than expected. Neither the 2020 killing of Qassem Soleimani nor last summer’s attack on the nuclear program produced the kind of wider conflagration that many (including myself) feared at the time.

Now, however, we are seeing the long-predicted escalation. Iran has, among other things, bombed surrounding Gulf nations and announced a kind of blockade on the Straits of Hormuz, a key international shipping lane. 

Moreover, the prior rounds of attacks have deepened Iran’s fears about a potential regime change operation — leading the Islamic Republic to take steps to ensure continuity against any kind of regime change. Worried in particular about the decapitation strikes Israel used so effectively against its proxies Hamas and Hezbollah, the government took steps to create institutions, like the new Iranian Defense Council, that could ensure continuity in the event that a top leader would be killed. 

The regime’s bureaucratic structure is a big reason why the killing of Supreme Leader Ali Khamenei has seemingly done little to destabilize Iran. The aging cleric was not a Putin figure, the indispensable man on whom the regime depended. Both top generals in Iran’s elite Revolutionary Guard Corps and high-ranking civilians, like national security council leader Ali Larijani, were positioned to continue guiding policy in the event of Khamenei’s death.

“Everything…that we’re seeing indicates that the leadership is still fully in control, and there are no particular signs that a revolt if the people took to the streets right now that they would be able to overthrow the government,” says Ken Pollack, the vice president for policy at the Middle East Institute think tank. “Hopefully the Iranian military will figure out that sticking with this regime is a loser of a proposition and won’t fight on their behalf. It’s just that we’ve not seen any evidence of that.”

Indeed, most experts say it’s unlikely that the bombing will ever inspire a coup that topples the regime: The military already plays a major role in political decisions, so they would effectively be toppling themselves. And while it remains possible that the bombing inspires a popular uprising, it is vanishingly unlikely.

When Iranians took to the streets to protest en masse this January, the regime crushed them: slaughtering as many as 30,000 people in a horrifyingly short span of time. For the bombing to prompt another uprising, people would need to have some reason to believe the outcome would be different. Yet no aerial campaign has ever so thoroughly decimated an authoritarian government’s ground forces that a popular movement successfully rose up against them.

When US-led regime change from the air does work, as in Libya in 2011, it is because American airpower is backing armed forces on the ground. But Iran is not in a state of civil war: there is no well-armed opposition to speak of, nor is there evidence of fracture inside its uniformed forces.

“We see no indications that security forces hesitated to crack down in the past several months,” says Marie Harf, the executive director of the University of Pennsylvania’s Perry World House (where I am currently a fellow).

The more likely scenarios are more modest

While regime change appears unlikely to the experts, the more plausible scenario is that the war ends short of that. 

“It almost seems inevitable to me that President Trump is going to dial back whatever his more maximalist vision is and settle for something less,” says Michael Koplow, the chief policy officer of the Israel Policy Forum think tank.

There are a range of possibilities for what that might look like. The most obvious one, even bandied about by Trump himself, is the “Venezuela model”: where Trump strikes some kind of deal with a post-Khamenei Iranian leader that he believes constitutes a real gain for the United States (and him personally).

Such a deal might look quite literally like one in Venezuela, in the sense that Iran provides concessions on oil production and sales that privilege the United States. Trump has been interested in seizing control of Iranian oil since the 1980s, so some agreement on that era might be enough for him to back off.

It also might relate to the more typical grievances the US has with Iran: Iran’s nuclear program, its ballistic missile production, or (less likely) its support for militias abroad like Hamas, Hezbollah, or the Houthis. Were Trump to get major concessions in those areas, he could claim that force achieved what diplomacy could not — and thus have a decent justification for ending the war.

It would likely take time for any such negotiations to produce an acceptable outcome. “I think these guys will immediately not make a deal, because they need to show they are not pushovers. But then they ultimately will,” says Arash Azizi, an Iran expert at Yale University.

It’s possible, as the war rages, that political pressure mounts on the Trump administration to back down before an agreement could be struck. There have already been six US deaths during the conflict, and there could be more. Nearby Gulf states are taking a lot of damage, and so too could the global economy if hostilities last too long.

If negotiations look to be dragging, there is a chance that Trump declares victory and goes home. Killing Khamenei, and doing more physical damage to Iran’s nuclear program and ballistic missile sites, might provide a plausible enough fig leaf for the US to simply say it has accomplished what it wanted to and end the war.

“It almost seems inevitable to me that President Trump is going to dial back whatever his more maximalist vision is and settle for something less.”

Michael Koplow

This would likely change very little on the ground — and is probably Iran’s best-case scenario. But it’s in keeping with Trump’s typical approach, especially when markets start to panic.

Either outcome, a Venezuela-style negotiation or unilateral US withdrawal, would infuriate a key stakeholder: Israeli Prime Minister Benjamin Netanyahu. But while Netanyahu reportedly played an important role in convincing the Trump administration to go to war, his influence over its duration is relatively limited.

“Israel is not built for long wars in general, definitely not a long war as it comes to Iran. So I think in many ways, what will determine the length of this war will be more decisions made in Washington than in Jerusalem,” says Eyal Hulata, the former head of Israel’s national security council. “If I try to understand how the Americans are looking at it, the ball is in the Iranian court as it comes to how long this will end and what kind of concessions Iran will be willing to make.”

The tail risk: Iraq 2.0

The last outcome, and the most dangerous, is that the United States decides that it will not stop until regime change happens.

The consensus is that this is unlikely. Most observers, both in Washington and Tehran, believe that the Americans do not have the stomach for another major ground war in the Middle East. Trump has publicly left the door open to ground troops, but this is widely seen as something of a bluff.

But what if it isn’t?

Michael Hanna, the director of the US program at the International Crisis Group, floated a scenario where Iran pulls off a major attack on US assets: killing dozens of American soldiers in a single strike, or taking down an American warship in the Gulf.

In such a situation, he argues, the Trump administration would feel the need to respond more aggressively, likely encouraged by Netanyahu. The more the US escalates, the more likely Iran is to respond in a way that produces further US casualties — creating an escalatory cycle militating towards deeper and deeper American involvement inside Iran.

Once such a cycle begins, Hanna says, “all bets are off”; events take on their own logic. A ground deployment that nobody at present wants or really can even imagine would enter the realm of possibility. Such a deployment could lead to an extended US ground occupation, an Iranian civil war, or any number of (almost certainly) catastrophic outcomes.

This is what statisticians call a “tail risk”: an extreme outcome that is at the very end of the probability distribution. The most likely outcomes remain in the more restrained range: some kind of negotiated settlement or a unilateral US declaration of victory.

But escalation is not impossible: War is extremely unpredictable, especially a conflict that has already spread to an entire region. What Trump has begun is not fully under his control; the president’s skepticism about big ground wars does not guarantee that he will dodge one.

George W. Bush ran as an intervention skeptic in the 2000 presidential election. An unforeseen tail risk, the 9/11 attacks, changed his presidency. There is a distant-but-real chance the US is on the cusp of something similar.

Josh Keating contributed reporting to this piece.