The Possible Endings of the United States–Israel War with Iran

Wednesday 18 March 2026

The war that erupted on 28 February 2026 when the United States and Israel launched coordinated strikes against Iran has already reshaped the strategic landscape of the Middle East. The initial attacks targeted Iranian military and leadership infrastructure and reportedly killed Iran’s Supreme Leader, Ayatollah Ali Khamenei. Iran responded with missile and drone strikes on Israel and United States facilities in the Gulf, while Iranian-aligned militias such as Hezbollah entered the conflict. 

Within days the confrontation spilled into global economic systems. Shipping through the Strait of Hormuz — through which roughly one quarter of global seaborne energy normally passes — was severely disrupted, pushing oil prices above $100 per barrel and shaking financial markets. 

Wars of this nature rarely end through a single decisive act. Instead they tend to conclude through one of several broad patterns: decisive victory, negotiated settlement, frozen conflict or systemic collapse. In the case of the United States–Israel war with Iran, four plausible outcomes presently dominate strategic discussion.

1. Rapid Strategic Defeat of Iran

The first and most dramatic scenario is a relatively swift military collapse of the Iranian state apparatus.

Iran’s armed forces have already sustained significant damage from American and Israeli strikes targeting naval units, missile infrastructure and command facilities. United States forces alone have reportedly struck more than ninety military targets and destroyed or damaged over one hundred Iranian naval vessels. 

In this scenario continued strikes destroy enough of Iran’s air defences, missile forces and Revolutionary Guard command structures that the government can no longer effectively prosecute the war. Internal unrest, already present in Iran’s strained economy, could then trigger political collapse.

Several analysts believe the conflict might last only a short period if Iranian retaliation proves limited. One estimate suggests a roughly sixty per cent probability that the main phase of the war could end within weeks because of the overwhelming disparity in conventional military power. 

The timeline for such an outcome would be measured in weeks or months, not years.

However this outcome carries paradoxical risks. A collapsed Iranian state might not produce stability. Instead it could create a power vacuum filled by competing armed factions. Some analysts suggest that the most likely successor structure would be a military-dominated regime under the Islamic Revolutionary Guard Corps rather than a democratic government. 

A rapid defeat of Iran would dramatically alter Middle Eastern geopolitics.

Israel would emerge as the region’s unchallenged military power. Gulf monarchies would move closer to Washington for security guarantees. Iran’s network of proxy forces — Hezbollah, militias in Iraq and Syria, and the Houthis in Yemen — would lose their principal sponsor.

Yet such a victory might also produce new instability. Iran’s collapse could resemble Iraq after 2003: fragmented governance, competing militias and prolonged insurgency.

Economically, a swift end to the war would likely stabilise global energy markets relatively quickly. Oil prices might fall once shipping routes reopen and Iranian export capacity gradually returns.

Nevertheless long-term economic disruption would persist. Iranian infrastructure damage and capital flight would take years to repair.

2. Limited War Ending in Negotiated Settlement

The second scenario is a limited war followed by negotiated de-escalation.

Under this outcome both sides reach the conclusion that continued escalation produces diminishing returns. The war therefore ends through diplomatic mediation, possibly involving European states, China or the United Nations.

Such an arrangement might resemble the ceasefires that ended earlier Middle Eastern wars: the combatants remain hostile, but active hostilities cease.

Economic pressure may drive this outcome. Disruptions to shipping in the Strait of Hormuz already threaten global energy markets, affecting approximately twenty per cent of world oil supply. 

Mounting global economic costs could force diplomatic intervention. Analysts have already suggested that rising oil prices and maritime disruptions may create incentives for a ceasefire even without a full political settlement. 

This scenario may be the single most probable outcome in geopolitical terms.

Major powers rarely permit prolonged disruption of a strategic chokepoint such as Hormuz. International pressure therefore tends to favour compromise once both sides have demonstrated military resolve.

The likely timeline would be three to six months of hostilities followed by an uneasy ceasefire.

A negotiated settlement would leave the regional balance of power largely unchanged.

Iran would remain hostile to Israel and the United States, while Israel would claim strategic success if Iranian nuclear or missile programmes were significantly degraded.

However the war would intensify regional polarisation. Gulf states might strengthen defence ties with the United States, while Iran could move closer to Russia and China.

The principal geoeconomic impact would be a period of volatility in energy markets.

Even a short disruption in Gulf shipping can cause dramatic price spikes. Brent crude prices surged from roughly $70 to more than $110 per barrel after the war began. 

A ceasefire would eventually reduce prices, but investors would price a permanent geopolitical risk premium into Middle Eastern energy exports.

3. Prolonged Regional War

The third scenario is a wider regional war lasting several years.

In this case Iran avoids outright defeat by relying on asymmetric warfare. Tehran has long cultivated regional proxies capable of attacking Israel and United States interests across multiple theatres.

The conflict has already begun to expand beyond Iran itself. Hezbollah rocket attacks from Lebanon have triggered Israeli counter-strikes, and the war now spans multiple fronts. 

If additional actors join the conflict — including Iraqi militias, the Houthis in Yemen or Syrian forces — the war could transform into a broad regional confrontation.

Although less likely than a limited conflict, this scenario cannot be dismissed.

If Iran’s leadership believes the regime itself is at risk, it may escalate dramatically rather than concede defeat. In such circumstances the war might last two to five years.

A prolonged regional war would transform Middle Eastern politics.

Israel would remain under constant missile threat from multiple directions. Gulf monarchies might become direct battlefields. Global diplomatic alignments could shift as China, Russia and European states attempt to prevent further escalation.

The conflict might even trigger nuclear proliferation pressures if regional states conclude that only nuclear deterrence can guarantee their survival.

The economic impact of a multi-year war would be profound.

Repeated disruption of the Strait of Hormuz would destabilise global energy markets and potentially trigger worldwide recession. Shipping insurance rates would remain elevated and global supply chains would be repeatedly interrupted.

The war could also accelerate structural changes in the global energy system, encouraging faster investment in alternative energy sources and new transport corridors.

4. Strategic Withdrawal of the United States with Iran Intact

A fourth and distinct outcome is one in which the United States elects to terminate her direct participation in the conflict and withdraws from the theatre, notwithstanding the continued survival of the Iranian government.

This scenario would not arise from battlefield defeat in the conventional sense. Rather it would reflect a political decision in Washington that the costs of continued engagement outweigh the strategic benefits — a calculation shaped by domestic opinion, fiscal constraints, global commitments elsewhere and the risks of escalation into a wider regional or even great-power confrontation.

Such decisions have precedent. The United States has on multiple occasions disengaged from conflicts in circumstances short of decisive victory, where the continuation of operations threatened to produce diminishing returns or unacceptable risks. In the present case, sustained disruption to global markets, escalating regional proxy warfare and the possibility of attacks on United States personnel or infrastructure across the Middle East could all combine to create pressure for withdrawal.

At present this outcome appears more plausible than outright Iranian collapse or a prolonged multi-year regional war.

Its likelihood would increase significantly if three conditions emerge simultaneously:

• mounting casualties or material losses for United States forces

• sustained economic disruption affecting domestic American markets, including energy prices and financial stability

• political pressure within the United States, particularly in an electoral cycle or amid competing global priorities

Under such conditions, a decision to disengage could be taken relatively quickly. The timeline for withdrawal might be measured in weeks following a political decision, although the build-up to that decision could take several months of inconclusive conflict.

A United States withdrawal, leaving Iran’s government intact, would reverberate across the Middle East and beyond.

Israel would find herself in a significantly altered strategic position. Without direct American participation in combat operations she would face the prospect of continuing hostilities with Iran and her proxies largely alone, albeit with ongoing intelligence and logistical support from Washington. This could either compel Israel to escalate independently or, more likely, incentivise her to seek her own ceasefire arrangements.

Iran, by contrast, would claim strategic victory simply by virtue of regime survival. The narrative of having withstood a combined United States–Israeli assault would strengthen her position domestically and across the so-called “axis of resistance”. Tehran’s regional proxies — from Lebanon to Yemen — would likely be emboldened, interpreting American withdrawal as evidence of declining Western resolve.

Amongst the Gulf states, confidence in United States security guarantees would be shaken. Some would deepen bilateral defence arrangements with Washington; others might pursue a more hedged strategy, improving relations with Iran or diversifying their security partnerships, potentially including China.

At the level of global geopolitics, such a withdrawal would be closely scrutinised by other powers. Moscow and Beijing would likely interpret it as confirmation that the United States is increasingly reluctant to sustain protracted military engagements in complex theatres. This perception could influence strategic calculations in regions far removed from the Middle East, including Eastern Europe and the Indo-Pacific.

The economic consequences of a United States exit would be immediate yet ambiguous.

In the short term markets might respond positively to the prospect of de-escalation, particularly if withdrawal reduces the intensity of hostilities in and around the Strait of Hormuz. Shipping lanes could partially reopen, and energy prices might stabilise after an initial period of volatility.

However this stabilisation would be fragile. Without a comprehensive political settlement, the underlying risk to Gulf energy infrastructure and maritime transit would persist. Insurance costs for shipping would remain elevated, and investors would continue to price geopolitical risk into energy markets.

Moreover, the longer-term geoeconomic implications could be profound. A perceived retreat of United States power from the Gulf might accelerate structural shifts in global energy trade. Asian powers, particularly China, could seek to play a more prominent role in securing maritime routes and negotiating regional security arrangements tied to energy supply.

At the same time, American allies in Europe and Asia might reassess their own strategic dependencies, potentially investing more heavily in energy diversification, domestic production or alternative supply corridors.

This scenario represents neither victory nor defeat in conventional terms. Instead it reflects a recalibration of priorities — a decision that the preservation of broader strategic flexibility outweighs the pursuit of a definitive outcome in a single theatre.

Its principal danger lies in perception. While withdrawal might reduce immediate risks to United States forces and limit economic disruption, it could also be interpreted by adversaries as a signal of strategic fatigue.

Yet history suggests that such interpretations are often contingent rather than fixed. Much would depend on how withdrawal is framed — whether as a temporary disengagement within a broader strategic posture, or as an abandonment of regional commitments.

In this respect the manner of departure may prove as consequential as the departure itself.

Can we make any predictions?

Wars between major regional powers seldom end in tidy or predictable ways. The United States–Israel war with Iran is particularly complex because it combines direct state conflict, proxy warfare, global energy markets and ideological rivalry.

Four broad outcomes presently dominate strategic thinking: a rapid Iranian defeat, a negotiated settlement, a prolonged regional war or the internal collapse of the Iranian state.

Of these possibilities the most likely near-term outcome is a limited conflict followed by diplomatic de-escalation, primarily because the global economic consequences of prolonged disruption to the Strait of Hormuz are intolerable to the world’s major powers.

Yet the most consequential scenario may be regime collapse in Iran. Such an event would transform Middle Eastern geopolitics more profoundly than any battlefield victory; but at the current time the Iranian regime is proving more resilient than many would have expected.

The decisive factor will not necessarily be military power. Rather it will be the interaction between military pressure, economic disruption and political resilience inside Iran itself — a combination that history shows can produce outcomes far more dramatic than even the most carefully planned wars anticipate.