President Trump has tweeted many times about the need to wind down “endless wars” in the Middle East — and held off from launching a military response to last year’s Iranian provocations in the Persian Gulf. But to many analysts, the killing of Iranian Maj. Gen. Qasem Soleimani raises the question of whether Trump wants war with Iran.

Trump’s motivations — and the answer to this question — remain unclear, but there’s little doubt about one point: Many in the Trump administration want regime change in Iran. The departure of notorious Iran hawk John Bolton as national security adviser has done little to change that. As New Yorker columnist Dexter Filkins said in a recent interview, “Everyone around President Trump if not President Trump himself favors regime change.”

But how would the United States overthrow the Iranian regime? Political science research suggests there are few good options.

What is regime change, exactly?

Scholars define regime change as “the forcible or coerced removal of the effective leader of one state — which remains formally sovereign afterward — by the government of another state.” In Iran’s case, that leader would be President Hassan Rouhani or, alternatively, Supreme Leader Ali Khamenei.

Interveners may also install or help select a new leader, as the United States did when it replaced Guatemalan President Jacobo Ábenz with Carlos Castillo Armas in 1954. But the U.S. and its NATO allies supported the Libyan rebels in 2011 — while outsiders had little say in determining who would rule Libya after Moammar Gaddafi’s fall.

Interveners in some cases also overhaul the governing institutions of the target country, as the U.S. did when it sought to democratize Afghanistan and Iraq, but this type of “full” or “institutional” regime change is relatively rare.

4 ways the U.S. could change the Iranian regime

The United States has four basic options:

1. Invasion

The most reliable option — but also the most far-fetched in this instance — is to invade Iran; kill, arrest or drive its leaders into exile; and impose a new regime.

The upside of this method is that it almost always achieves its goal. The downside is the “Pottery Barn” rule: You break it, you buy it. As the U.S. government has discovered more than once, getting in is a lot easier than getting out.

Could the U.S. military defeat Iranian forces in an all-out war? Yes — but occupying a country four times the size of Iraq with an ethnically diverse population more than three times that of Iraq’s 2003 population would court disaster.

2. Air power

The U.S. could use air power to try to “decapitate” Iran’s leaders just as it killed Soleimani — and attempted to kill Gaddafi in 1986 and Saddam Hussein in 1991 and 2003.

The upside of this method is that it is low cost and avoids putting U.S. boots on the ground. The downsides? It’s hard to target a head of state using air power — it has never been done successfully — and Washington would have no control over who takes power next.

Decapitation requires flawless real-time intelligence on the target’s whereabouts and the ability to deliver ordnance to a precise location at the right time. This is much easier to do over friendly territory — hence the use of a loitering drone to target Soleimani in Iraq. It’s unclear why decapitation would be a more viable strategy in Iran than it has been elsewhere in the past.

Even if airstrikes did succeed in killing Rouhani or Khameini, would it be worth it? The massive turnout of Iranian mourners angry at Soleimani’s killing suggests decapitation is unlikely to spark a revolution or the collapse of the regime.

The Trump administration would also be open to the charge that it had assassinated a foreign leader, which would be true unless the U.S. and Iran were at war.

3. Coercion

Third, the United States could try to coerce Iran’s leaders to give up power, such as by imposing additional economic sanctions or threatening military action. The upside of this method is that it is cheap.

But economic sanctions have never by themselves caused a leader to abdicate. Current sanctions on Iran are crippling, but there is no sign that the regime is on the verge of cracking. Iran’s leaders, in fact, were able to repress a number of domestic protests in recent months.

Threats to change a regime by force can succeed — but only when the coercer is vastly more powerful than the target and poses a credible threat of invasion. These conditions do not hold in the case of Iran.

And again, Iran’s next leader might be just as antagonistic toward the United States.

4. Cooperation with local opposition groups

A final option is for the U.S. to work overtly or covertly with those inside Iran who seek regime change. Recent studies have found that the existence of viable opposition groups makes regime change more likely. During the Cold War, Washington attempted 64 covert regime changes, most of which entailed cooperation with or support for local groups. One notable success was the 1953 overthrow of Mohammad Mossadegh in Iran.

Covert operations tend to be cheap and sometimes deniable. But they fail more often than they succeed and the intervener’s secret role rarely stays secret.

In this case, working with dissident Iranians inside or outside the country is not a feasible option.

The leading dissident organization, the Albania-based Mujahedin-e-Khalq (MEK), has no presence in Iran, not to mention a highly dubious past.

Kurdish militant organizations, such as the KDPI and PJAK, are based in northern Iraq and have a limited presence in Iran. The Baluchi group Jundullah (or Jaish al-Adl) carries out attacks in southeastern Iran but has as few as 100 fighters.

The U.S. government has designated all of these groups except the KDPI as terrorist organizations, at one time or another. It’s difficult to see any of these groups as serious potential partners for regime change operations in Iran.

So what seems likely to happen?

In short, there are no good options for effecting regime change in Iran in a way that is at once low cost, likely to work and likely to yield a government friendly to Washington.

If the Trump administration has a strategy in Iran, it appears to be one of hope — the hope that suffocating sanctions will spark a popular uprising against the regime. If so, it would be unprecedented in the history of regime change.

Alexander B. Downes is associate professor of political science and international affairs at George Washington University. He is the author of Targeting Civilians in War (Cornell University Press, 2008) and several articles and a book manuscript on the effects of foreign-imposed regime change.

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