Where the War With Iran Goes From Here

Scenarios for how the war ends and what it could mean for Iran, Israel, the region and U.S. strategy

Credit: US Navy

When I worked at the Pentagon fifteen years ago on the Iran desk, we had comprehensive plans for the possibility of a war with Iran. One of the key questions we asked the military planners was simple: What does Phase IV look like? In military planning, Phase IV is post-conflict stabilization – the plan for what happens after the fighting stops.

The answer we got back was revealing: “That’s really up to the civilians.”

In other words, there was no plan. This was not long after the debacle of postwar planning in Iraq in 2003, and deferring it to others simply wasn’t a good enough answer. So for months, I was part of an interagency process involving the State Department, CENTCOM, the Joint Staff and the Office of the Secretary of Defense. We debated and developed scenarios for what Iran might look like after a major or even limited war with the United States and ultimately gave the military direction and parameters that they used to plan.

Military planners often say that the purpose of planning is not the plan itself. Plans rarely survive first contact with reality. The real value is the process: thinking through scenarios, consequences and options before events force decisions upon you.

Fifteen years later, those experiences still shape how I think about the moment we’re in now. So the question is unavoidable: Where does this war go from here?

Let me walk through the key factors I am watching, the scenarios that could emerge and what they would mean for Iran, the region and the United States.

The Key Factors That Will Shape the Outcome

The first lesson from that Pentagon exercise was simple but crucial: The post-conflict outcome depends heavily on how the conflict itself unfolds. Right now, three major factors will determine how this war ends.

First, at the most basic level, the war’s trajectory depends on the military contest between Iran’s missile and drone arsenal and the missile and drone defensive systems of Israel, the United States and the Gulf States.

So far, the United States and Israel have had considerable success in degrading Iran’s ability to launch large salvos toward Israel. But Iran continues to launch drones and shorter-range missiles at U.S. and civilian and energy infrastructure targets across the Gulf while the U.S. continues to try to destroy them.

If that balance shifts dramatically in one direction or the other, it could shape the war’s endgame.

If Iran retains enough capability to impose real costs – wearing down interceptors or hitting key regional targets – it may secure better terms or prolong the conflict. But if Iran’s capabilities collapse and the United States and Israel can operate with near impunity, that would produce a very different outcome.

The second variable is domestic politics – particularly in the United States.

Wars are sustained politically as much as militarily. And this one is already deeply unpopular with the American public. Polling suggests roughly 60 percent or more disapprove, and the conflict has barely begun.

Oil prices are rising, feeding inflation. U.S. allies in the Gulf are furious with Tehran but also deeply anxious about their own security.

All of that raises a key question: How long does Donald Trump want to sustain this war? Does he push for maximal pressure and escalation? Or does he declare victory quickly and move on? Trump’s own attention span – and his tolerance for rising costs – could be decisive.

The third factor is far murkier. Reports suggest the United States and Israel may be supporting Iranian separatist groups – particularly Kurdish groups operating along the Iraq-Iran border. Other minority regions could also come into play: Baluchi groups near Pakistan or Arab groups in Southwest Iran.

If the United States and Israel begin actively encouraging internal armed movements inside Iran, it could fundamentally reshape the trajectory of the conflict.

Even if Washington is cautious, Israel may be pursuing some of these efforts independently. That possibility introduces a third – and highly unpredictable – variable.

Given these variables, how might a conflict unfold?

Iran as Saddam’s Iraq in the 1990s

The most likely outcome by far, in my view, is something that looks a lot like Iraq after the 1991 Gulf War.

In that scenario, the United States and Israel severely degrade Iran’s military capabilities. Iran’s navy is crippled. Much of its ballistic missile program is destroyed. Its nuclear program is set back.

But the regime survives.

After the death of Supreme Leader Ali Khamenei, power passes to another hardliner, such as his son Mojtaba Khamenei, strengthening the role of the Islamic Revolutionary Guard Corps.

The war ends not because the regime collapses, but because the costs of continuing it become too high for everyone involved.

Iran emerges weakened but intact – a diminished but still dangerous adversary that is more aggressive and has less to lose.

That would mean a future resembling the long standoff with Saddam Hussein in the 1990s: sanctions, sporadic clashes, missile strikes and constant tension.

For the Iranian people, this would be devastating. The regime remains in power, but the country is economically shattered.

For the region, instability becomes the new normal. Gulf shipping lanes remain vulnerable. Oil prices stay elevated. Countries like Saudi Arabia and the UAE see their long-term economic transformation projects threatened by persistent insecurity.

For Israel, the threat never truly disappears. Missile attacks and periodic escalations remain possible for years.

For the United States, the consequences would also be terrible.

Managing Saddam in the 1990s required massive U.S. military deployments, permanent carrier presence and continuous air operations.

Something similar would likely happen again. American forces would remain deeply engaged in the Middle East – precisely the outcome that three consecutive presidents, from Barack Obama to Joe Biden to Donald Trump, claimed they wanted to avoid.

And as the 1990s showed, unintended consequences follow.

The large American military presence in the region became a rallying cry for Osama bin Laden and helped fuel the rise of al-Qaeda.

No one can predict exactly what the ripple effects of this war will be – but history suggests they will be significant.

Meanwhile, two countries would benefit strategically.

China would welcome an America bogged down in the Middle East while Beijing focuses on expanding its power in Asia and preparing for potential conflict over Taiwan. Though it would suffer from higher energy prices and a less secure supply.

Russia would benefit from sustained high oil prices – an economic lifeline for Vladimir Putin as Moscow struggles under the costs of the war in Ukraine.

A Regime Transition

A second possibility – significantly less likely but far better – is a leadership transition within the Islamic Republic.

This would not mean democracy. It would not mean Iran abandoning nationalism or suddenly becoming a Western ally.

But it could mean a more pragmatic leadership emerging in Tehran – one that decides Iran’s nuclear ambitions, missile program and regional proxy wars have become too costly.

There are figures within the Iranian system who might argue for such a shift.

One example is Hassan Khomeini, the grandson of Ruhollah Khomeini. He has ties to reformist circles while still maintaining credibility within the establishment.

If this happened, the benefits would be significant.

Iran could reintegrate economically into the region. Sanctions might ease. Regional tensions could decline. The U.S. would not get bogged down in the Middle East again. But this outcome requires three things that are far from guaranteed and could be quite unlikely.

First, the Iranian government would essentially have to capitulate. And right now, sentiment feels like it is going in the opposite direction. Even a more moderate leadership might not be willing to go far enough for this outcome to work.

Second, Trump would have to take yes for an answer – accepting a deal short of total Iranian surrender and regime change. That part feels quite plausible if he is looking for a way out. And in fact, his behavior in Venezuela would indicate that if he can find his Iranian Delcy Rodriguez and declare victory, he’d be happy to do so.

Finally, Netanyahu would have to accept such a transition instead of continuing to undermine it, and Trump would have to restrain him to get him to accept this outcome. Right now, it appears Netanyahu believes any version of the Islamic Republic must ultimately collapse, which would cause him to act against and try to kill even this more moderate leadership if it came about.

State Collapse – The Syria or Libya Outcome

The worst scenario is state fracture and civil war. Iran has existed as a unified civilization for more than 2,500 years. That deep national identity makes collapse less likely than in places like Syria or Iraq. But it is not impossible.

If outside powers begin arming separatist groups, the country could fracture. That is why reports of Trump making calls to Kurdish leadership in Iraq and of the U.S. and Israel supporting a potential Kurdish offensive are so disturbing. Kurds in the northwest, Baluchis in the southeast, Arabs in the southwest – all could become focal points for armed movements.

Once that process begins, it is unlikely to lead to a fast collapse of the regime and a shift in government. We are talking about a massive country with 90 million people. To militarily overthrow the Islamic Republic would be prolonged and messy.

There would also be spillover effects. Regional powers would intervene. Turkey might move to counter Kurdish groups. Saudi Arabia might support Arab factions. Pakistan could intervene along its border. External powers like Russia or China might back the central government.

Iran could become a proxy battleground on a scale even larger than Syria. The humanitarian consequences could be catastrophic, with the potential for a refugee crisis that dwarfs the Syrian one.

Power vacuums in Iran could spread instability and terrorism to places like Iraq, Afghanistan and Pakistan. We have seen this show before in this region, time and time again, over the past fifty years.

For the United States, this would mean years of renewed military involvement. For global energy markets, it would mean sustained volatility and higher prices.

Even Israel would face consequences. If Iran collapsed into chaos, the entire world would likely blame Israel and the United States for triggering the disaster, further eroding international support and deepening Israel’s isolation.

The Fantasy Scenario

There is also a fourth possibility frequently discussed in the run-up to the war and by Trump: that the Iranian people simply rise up and overthrow the regime. Or that someone like Reza Pahlavi, the son of Iran’s last shah, returns to power.

But this scenario faces a basic problem. With what army?

Iran’s opposition movements are brave but fragmented. The regime has shown repeatedly that it is willing to use overwhelming violence to suppress protests. In January, security forces brutally killed thousands of demonstrators. And there are no signs that Iran’s security forces will simply put down their arms and peacefully allow unarmed protestors to stand up and take over.

I want this possibility to be true and real. But the U.S. cannot be investing in a major new war in the Middle East on the basis that this is the outcome we will see, given how unlikely and ahistorical the scenario is.

The Way Forward

So what do these scenarios tell us about the way forward?

The first conclusion is obvious. This war should never have happened. A realistic assessment of the possible outcomes – and serious post-conflict planning – would likely have led to a different conclusion.

The United States had another option. I wrote about it a few weeks ago with my former colleague Nate Swanson. After recent protests inside Iran, the regime was already under enormous pressure. Its leadership was aging. The country was economically strained.

A strategy of containment and pressure – combined with support for Iranian civil society and human rights – might have allowed the system to evolve or fracture internally.

That approach was not guaranteed to succeed. But it would have been far less risky than launching a costly war whose most likely outcomes are deeply problematic.

At this point, the best option is to try to steer events toward a managed transition while avoiding steps that push Iran toward collapse.

That means signaling clearly that a more pragmatic Iranian government – one that reduces regional aggression and responds to its own people – could receive sanctions relief and economic reintegration. It means restraining Israel from actions that would sabotage such an outcome and could lead to collapse. And it means recognizing that the most likely outcome remains the first scenario: A weakened but still hostile regime and a new long-term American commitment to the Middle East.

Even if the Trump Administration does everything right (And I am quite skeptical they will), achieving a stable transition would be the geopolitical equivalent of drawing an inside straight. Most of the possible outcomes are bad. Which is exactly why Trump should have thought much more carefully before starting down this path.