What’s next for Iran—and the world?

As airstrikes from the United States and Israel continue across Iran, questions abound for what comes next—from the future of Iran’s leadership to the fears of a wider war.

We asked University of Chicago experts to weigh in on the crisis: UChicago Law JSD candidate Pegah Banihashemi, an Iranian Constitution scholar and human rights instructor; Prof. Robert Pape, a political scientist who researches international security affairs; energy economics expert Prof. Ryan Kellogg; Prof. Tom Ginsburg, a scholar of international law; and Assoc. Prof. Paul Poast, who researches international relations.

In this edited Q&A, they discuss the history of regime change through air power, the legal authority for the war, what Ayatollah Ali Khamenei’s death means for Iran’s political future and how the conflict is reshaping alliances from Europe to the Gulf.

Editor's note: This piece has been updated to include analysis of the conflict's impact on global energy markets.

What would meaningful reform look like in Iran, and what are the obstacles? 

Banihashemi: Many Iranians aspire to a democratic order grounded in equal rights for all citizens—particularly equality between men and women. Many also support a clear separation between religion and the state.

But a portion of Iranian society remains loyal to the current system, either for ideological reasons or because of financial and institutional ties to the state. For decades, the Iranian government has granted its loyal supporters various forms of preferential treatment—this has created structural inequalities.

At the same time, Iranian society is far from unified about the country’s political future. Some segments of the population support the restoration of the monarchy and hope that Reza Pahlavi, the son of Iran’s former Shah, might return and serve as a transitional leader. Others advocate for a democratic republic after the Islamic Republic. Iranian society is also composed of many different ethnic communities, as well as religious minorities, so a new system would need to navigate this landscape.

For now, a government that has left little room for peaceful protest has created a political impasse for many citizens. A growing number of Iranians feel that opportunities for civil resistance have been exhausted, and so some people—even if reluctantly—view the current war as a possible catalyst for political change, despite the immense risks.

What are the chances of regime change in Iran—and what has history taught us about targeted killings of leaders?

Pape: The Trump administration is up against the weight of history, not just simply Iran. 

For the past 100 years, there have been many attempts to topple regimes from the air, and in all that time, air power alone has never done it. Actually imposing regime change is pretty rare, because in order to really do that you need to wage not just a ground war, but a pretty brutal one with a lot of attrition, a lot of casualties, and you’ll be taking those too. In the Vietnam War, we never imposed regime change over North Vietnam [despite extended bombing campaigns]. 

In 1996, Russia assassinated Chechen leader Dzhokhar Dudayev with a precision missile strike. By operational standards, it was flawless. But instead of ending the resistance, it shifted power toward more radical commanders willing to escalate, fueling years of war.

There are numerous other examples of decapitations leading to tactical success by actually killing the target, but then the opponent usually lashes back in ways the air-power attacker did not expect. 

Iran is trying to block the Strait of Hormuz. What does that mean for global oil supply?

Kellogg: Before the conflict, about one-fifth of global oil supply passed through the Strait. The conflict has slowed that flow to a trickle. Some of the oil-producing Gulf states have managed to re-route some of their supply through pipelines that bypass the Strait, but still we are left with roughly 10% of “business as usual” global oil supply now unable to get to market. That is a large supply shortfall that has driven up oil prices.

What tools does the government have to bring down gas and oil prices?

Kellogg: Governments are working to mitigate the price impact by releasing oil from strategic reserves, and it is probable that private entities in the oil market are drawing on their stocks as well. These moves have likely dampened the oil price shock, but they are not large enough to completely offset it. Other levers that the U.S. government has—beyond opening the Strait through diplomacy or military power—are even more limited. There has been talk of issuing a temporary waiver of the Jones Act, which is a nearly 100-year-old statute that outlaws waterborne shipping of any product, including petroleum products, between U.S. ports unless the shipping is done on a U.S.-built, -owned and -crewed vessel. Waiving the Jones Act would decrease petroleum product prices on the U.S. East Coast, but likely just by a few pennies per gallon.

Does the Trump administration have the legal authority to conduct this military action without congressional approval?

Ginsburg: The Constitution assigns the power to declare war to the Congress, but this power has not been utilized since World War II, and general international practice has moved away from formal declarations. Instead, international law focuses on whether or not there has been an armed attack, or the presence of hostilities. In our national law, the executive is the commander in chief—successive presidents have used this to conduct many different levels of military activity abroad, without prior congressional authorization. 

The 1973 War Powers Resolution seeks to limit the time period in which U.S. forces can be deployed abroad without approval from Congress, but every president except Barack Obama has argued that the statute is unconstitutional. The bottom line is that, as a matter of practice, the president can go ahead for a limited period of time without approval. Efforts by House Democrats to limit the president last week were rejected, leading the administration to claim that Congress had reaffirmed the commander in chief’s constitutional authority “to protect the American people from the Iranian regime's murderous ambitions and imminent threats."

Does the killing of a head of state violate international law?

Ginsburg: Yes, sitting heads of state are protected under a 1973 Convention that provides immunity for a small number of official actors. Heads of state have complete immunity from legal process under customary international law. Both the arrest of former Venezuelan leader Nicholas Maduro and the assassination of Khomeini violated these rules.

How have U.S. allies in Europe responded to the war—and what does that mean for the alliance?

Poast: To this point, the NATO allies have been mixed in their support to the U.S. operation, at least publicly.

Some opposed the war, and this had a key influence on whether the U.S. would have the basing access that is so critical for conducting overseas military operations. This was initially exemplified by the controversy over the use of Diego Garcia, which is under British control. However, the British government eventually allowed for "defensive operations" to take off from the base. There is a similar controversy with Spain, who has so far held firm, drawing the Trump administration’s ire.

At the other extreme is Germany, with Chancellor Friedrich Merz meeting with Trump last week. During the press conference, he appeared to publicly agree with the points Trump was making about the operation. That's significant, as the most important U.S. base in Europe or the Middle East is the Ramstein Air Base in Germany.

But one shouldn't be deceived by the extremes. The European states are no fan of the Iranian regime. While NATO members may not agree with the timing of the war or even how the U.S. is conducting the war, the alliance as a whole is not going to stop the U.S.

What circumstances justify the use of military force under international law—especially without UN Security Council authorization?

Ginsburg: The United Nations Charter protects the territorial integrity of all states, and so limits any use of military force without explicit authorization from the UN Security Council acting under Chapter VII, which covers breaches of the peace and threats to peace. 

There is an exception: the Charter speaks of an “inherent” right of individual or collective self-defense if a country is subjected to an armed attack. Many believe that one can act even before an attack occurs, so long as it is imminent and there is no option but to respond. Thus, if Iran was about to attack Israel, the U.S. and Israel might have had an argument that they were acting in collective self-defense to eliminate the threat. 

But there was no such imminent attack, and we have not heard the administration make this explicit argument. Indeed, I have not seen any legal justification for the war. That’s not surprising, but it should be disturbing. It suggests that there is no conception of any restraint in using force abroad. Law has never been great at constraining power, but it has had some effect. 

Russia and China have stayed on the sidelines. What does that tell us about the limits of their partnership with Iran?

Poast: Russia and China are not going to rush into the war using their own armed forces. China in particular seems to be hedging its position. But recent reports indicate that Russia is already providing Iran with targeting intelligence. And other reports suggest that China is at least considering providing Iran with spare parts and components, along with financial assistance. 

It is likely that if the war continues and the Iranian regime shows an ability to survive, then both will step up their support. What is notable is, when this occurs, the U.S., China and Russia will be engaged in indirect fighting in two theaters on two continents, Ukraine and Iran. I know people don't like using the phrase "world war," but that is awfully close to any definition I would use for the phrase. 

Iran is striking neighbors such as Saudi Arabia, Qatar and the U.A.E. How does that change the nature of this conflict and the region’s power dynamics? 

Poast: These states have long opposed Iran, viewing its regime as bent on dominating the region. Indeed, a key motivation for the Abraham Accords started by the first Trump administration and then continued by Biden was to solidify a regional coalition with the shared vision of opposing Iran. While there were some diplomatic movements relatively recently among these states to attempt thawing relations with Iran, its nuclear program still served as an impediment. Many of these states oppose such a program and Saudi Arabia would be likely to acquire its own bomb if Iran did so.

Hence, it is not surprising that Iran would respond to the U.S. and Israel strikes by launching missiles at both Israel and other regional allies of the U.S. It's a way for Iran to sow chaos in the region, raising the costs of the U.S.-Israel operation. But at the same time, it serves to underscore the claims by the U.S. that Iran is a regional threat, one that needs to be neutralized permanently. Whether the U.S. can do that in a timely fashion and in a way that doesn't put its regional allies at further risk remains to be seen.

Pape: This makes the ruling governments in the Gulf States angry at Iran, but it builds wedges between these governments and the publics in their countries. The narrative from Iran is very clear in their public statements that this is all about helping Israel become the hegemon in the region, conquer more territory. As an example of why these wedges may be concerning, we can look at former Egyptian President Anwar Sadat, who in 1978 signed the Camp David Accords with Israel—and then had his own security forces turn their guns on him in backlash in 1981. So there are real differences between what the leaders might decide quietly what to do and what the public will accept.

What is Ayatollah Khamenei's legacy—and can the system he developed survive without him?

Banihashemi: From the early years of his leadership, it appeared that Khamenei understood how to structure the pillars of power in a way that would solidify the foundations of Iran’s system of velayat-e faqih, or rule by the Islamic jurist.

While he remained a religious authority respected by many believers, he left almost no space for peaceful political dissent. Waves of protest throughout his tenure were met with increasingly severe repression—the state demonstrated little hesitation in using force, often causing significant civilian casualties.

At the same time, Khamenei strengthened institutions that were personally loyal to the leadership, most notably the Islamic Revolutionary Guard Corps (IRGC) and its affiliated Basij forces. The IRGC functions primarily as a military force, but over time it expanded far beyond a conventional security role. It developed extensive involvement in major sectors of Iran’s economy, including construction, energy and infrastructure. As a result, the organization accumulated not only significant military capabilities but also vast economic resources, in many respects becoming even more powerful and influential than Iran’s regular national army.

Constitutional reforms adopted in 1989 further reinforced the authority of the supreme leader while reshaping Iran’s institutional balance in ways that limited the independence of other state bodies. One of the most consequential mechanisms that emerged from this was the vetting of candidates in elections, requiring those seeking to run for office to demonstrate loyalty to the political system and its ideological foundations. This ensures electoral competition occurs only within boundaries defined by the regime itself.

Mojtaba Khamenei has been chosen to succeed his father and will inherit his system of power. Yet his profile differs significantly. The younger Khamenei has rarely played a visible public role, and it is difficult to identify speeches, policy initiatives or executive positions that would provide a clear record of his leadership style. His religious standing among senior Shiite clerics is also less established than that of many traditional candidates for leadership. Nevertheless, for at least two decades he has often been described as a powerful behind-the-scenes figure within Iran’s political establishment.

The central question is not whether the structures of power remain formidable—they do—but whether the new leader will be able to manage and maintain this intricate network of authority with the same discipline and control that defined the previous era.