Khamenei is dead, his son Mojtaba is running a regime under bombardment, and three more senior officials have been killed in the last 72 hours alone. Iran launched 3,000 projectiles after the latest assassination. Trump says operations are "winding down" while deploying 5,500 more Marines and requesting new war funding. Iran's foreign minister has rejected every ceasefire offer. Nobody is negotiating. So what will actually end this war?

1. Oil Is the Clock (IEA, Energy Analysts)

The Strait of Hormuz is the single strongest predictor. When the global economy can't take it anymore, this war ends.

Ten million barrels a day are offline -- the largest supply disruption in history. The IEA called it the "greatest global energy and food security challenge in history." Brent crude has surged past $120 from a pre-war $72. The Strait of Hormuz is effectively shut to Western shipping, with 70% of GCC food imports disrupted. Iran, meanwhile, is still shipping oil through the Strait to China -- at least 11.7 million barrels since February 28.

The cost projections tell you the timeline. If this ends in weeks, oil falls back to $65 by year-end. If it drags to two months, we're looking at $130 a barrel through Q2. Six months or more means $150 average. Those numbers hit grocery prices, gas pumps, and voter sentiment in real time. The longer the Strait stays closed, the more unbearable the economic pain -- and not just for the countries at war.

2. Actually, It's Trump's Political Calendar (Atlantic Council, Domestic Analysts)

He needs a win before the midterms. That gives him an April-May window to declare victory and leave.

Trump initially promised four weeks. Then he said the war was "very complete, pretty much." Then he killed three more senior officials and sent more Marines. The contradiction tells you everything: the political need to end it is real, but the military temptation to keep going is stronger.

The 2026 midterms are the hard deadline he can't ignore. Domestic inflation from the oil spike is already a political problem. Some analysts predict an April-May window where Trump declares Iran's military "degraded beyond recovery," claims a historic victory, and begins withdrawal -- regardless of whether the regime has actually capitulated. The Venezuela playbook: kill the leader, claim the win, leave.

3. It Depends on If Mojtaba Consolidates (Foreign Policy, Atlantic Council)

If the new supreme leader consolidates, the regime hardens. If he doesn't, it might crack.

Mojtaba Khamenei was installed March 8 with IRGC backing, but he lacks his father's religious authority. The system has shifted from theocracy to a security state held together by coercion, not charisma. Experts give him 30-60 days to establish real control. If he succeeds, Iran adopts a more aggressive posture. If he falters, the regime may desperately seek an off-ramp.

The domestic situation is deteriorating. The rial has lost 40% of its value since February 28. Inflation was already at 60%. Protests erupted in mid-March -- chants of "Death to IRGC" and "Long Live Shah" -- and Chaharshanbe Suri celebrations on March 17 turned into open defiance. The IRGC threatened a crackdown "bigger than January." Nowruz started March 20 -- a cultural window that could become a flashpoint.

The CIA's assessment is carefully split. The regime is in a "deep command and control crisis" but shows "no sign of imminent collapse." That's the gap where the war's future lives.

4. The Houthis Are the Wild Card (Stimson Center, Proxy Analysts)

If the Houthis enter, this becomes uncontainable. If they stay out, it stays manageable.

Every proxy except the Houthis is already in. Hezbollah broke its ceasefire and resumed attacks. Iraqi militias have launched 67 drone and missile attacks on US bases. But the Houthis -- the one group that could turn a regional conflict into a global shipping crisis -- are holding back. Their weapon stockpile is depleted from the Gaza-era campaign, and analysts say they'll only fully commit if the war widens dramatically or Iran faces an existential threat.

The Houthi decision is binary. If they stay out, the conflict remains a US-Israel-vs-Iran air war with manageable proxy involvement. If they enter -- Red Sea shipping blockade, attacks on Saudi infrastructure, another front for the US military -- the four-week timeline becomes fantasy. The Stimson Center framed it as the single decision that determines whether this stays a war or becomes a crisis.

5. It Depends on When People Start Talking (Time, Atlantic Council)

The best predictor of when a war ends is when someone starts negotiating. Nobody has.

Iran has rejected every ceasefire offer. Araghchi's position is clear: the US started it, the US bears responsibility, and Iran will not accept a temporary pause -- only a permanent end. Trump has rejected ceasefire too, framing it as capitulation. Israel's defense minister said "no one has immunity -- everyone is a target."

The expert consensus is that quiet talks will eventually emerge, forced by oil pressure, by early summer. The Atlantic Council's most-cited scenario is the medium path: 2-6 months of continued strikes, quiet backchannel negotiations, and a deal forced by economic pain rather than military resolution. But right now, on Day 21, there is no named mediator, no public framework, and no conditions on the table. The Oman channel that nearly produced a deal on February 27 has not been revived.

Where This Lands

On Day 3, we said nobody knows. On Day 11, we said nobody agrees. On Day 21, we can be more specific: the war ends when one of five things breaks. When oil prices become politically unbearable for Trump -- likely April or May. When Mojtaba either consolidates the regime or loses control of it -- likely within 60 days. When the Houthis decide whether they're in or out. When someone, somewhere, starts a backchannel negotiation. Or when all five converge at once. The expert consensus says 2-6 months. Trump's political calendar says sooner. Iran's refusal to talk says later. The only certainty is that the longer nobody negotiates, the more the other four variables determine the outcome -- and none of them favor a clean ending.

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