Knowing when to stop out: US/Iran conflict

Drawing on Annie Duke's decision-making framework in Quit, this note examines four strategic paths for the U.S.-Iran conflict and argues that while continuing the campaign is the most likely near-term outcome, it is unlikely to become another forever war. As disruption to global energy and maritime trade accumulates, the global economy will increasingly narrow policymakers' options, making economic sustainability the ultimate constraint on the conflict.

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Knowing When to Stop Out: US/Iran War

"Entering a trade is easy. Exiting one is hard." — Anonymous Wall Street Trader
"It is always easy to begin a war, but very difficult to stop one." — Sallust

Financial markets impose a discipline that governments often struggle to match. Every investment is continually reassessed as new information emerges. Positions are adjusted, reduced, or closed because capital is finite and every additional dollar committed to one investment cannot be deployed elsewhere.

But wars rarely operate this way. Governments devote enormous effort to deciding when to enter a conflict. They define objectives, develop military plans, and describe what victory should look like. Far less attention is devoted to an equally important question: what evidence would justify changing the strategy or ending it altogether?

Annie Duke argues in Quit that disciplined decision-makers separate sunk costs from future expected value. Resources already committed cannot be recovered and should not determine the next decision. Every additional investment should stand on its own merits. That framework has become increasingly relevant in the U.S.-Iran conflict.

Unlike many previous wars, this conflict is not only consuming military resources, it is disrupting the world's most important energy and maritime trade corridors. Every additional month of fighting imposes costs not only on the governments involved, but on the global economy.

That will ultimately prevent this from becoming another forever war. As the economic costs of prolonged conflict continue to accumulate, the range of politically and economically viable options will continue to narrow. Whether policymakers choose to change course themselves or have their choices increasingly constrained by the global economy every additional military operation, diplomatic initiative, and dollar spent should answer a single question: Does the next investment improve the probability of achieving the United States' objectives?

Like any investor facing a changing market, the United States has (at least) four broad strategic choices.

Option 1: Comprehensive Peace: 10%

A disciplined investor's first instinct is to revisit the investment thesis. If the original thesis remains sound but new information suggests the current strategy is no longer the best path to achieving it, the position is adjusted. The objective remains the same but the strategy changes.

Applied to the Iran conflict, this would mean preserving the original objectives while fundamentally changing the strategy used to achieve them. Rather than relying primarily on military pressure, Washington would work to negotiate a comprehensive settlement addressing the underlying causes of the conflict. Building on the framework established by the June Memorandum of Understanding, such an agreement could combine nuclear restrictions, sanctions relief, regional security arrangements, verification mechanisms, and a longer-term framework for maritime security.

The greatest obstacle is credibility. Reaching another agreement may be easier than convincing either side it will survive. Without confidence that both governments will honor their commitments, a comprehensive settlement risks becoming another temporary pause rather than a durable peace.

Option 2: Maritime Settlement: 30%

Rather than pursuing every original objective, Washington could narrow its ambitions to the one offering the greatest immediate strategic return: restoring stability in the maritime domain.

Under this approach, the United States and Iran would negotiate a limited agreement reopening the Strait of Hormuz and Bab el-Mandeb under a new governance framework while leaving broader political disputes unresolved. Nuclear negotiations, sanctions, and regional competition could continue, but commercial shipping would once again become more predictable.

This would not produce a comprehensive peace. It would produce a managed peace. The broader strategic rivalry would continue, but both sides would conclude that keeping the world's most important maritime chokepoints open creates greater value than continuing to use them as instruments of pressure.

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Option 3: U.S. Withdrawal: 15%

The third option is for the United States to conclude that additional military operations no longer justify their military, economic, or political costs and begin disengaging from the conflict without achieving every original objective.

Such a decision would acknowledge that future investment is unlikely to produce a meaningfully better strategic outcome than preserving military, political, and economic resources for other priorities. The withdrawal could be initiated by the current administration, a future president, or indirectly through congressional funding constraints.

The strategic consequences would be significant. Iran would likely exercise greater influence over the future operating environment in the Strait of Hormuz, while the United States would rely increasingly on deterrence, sanctions, regional partnerships, and offshore military presence rather than continued direct military operations.

Option 4: Prolong the War: 45%

The runway for a prolonged conflict is getting shorter, but it remains the most likely near-term path.

Wall Street has an old saying: "When in trouble, double." Every investor understands the temptation. Wars present the same temptation. Continuing the campaign is entirely rational if policymakers genuinely believe additional military pressure materially improves the probability of achieving their objectives. The danger begins when the basis for the decision changes. Instead of asking whether the next military operation improves the probability of success, policymakers begin asking how to justify the resources already committed. Military deployments justify additional deployments. Political credibility begins outweighing strategic value. Yesterday's investment begins determining tomorrow's decision.

History suggests governments often persist because changing course appears more politically costly than continuing the fight. That makes continuing the campaign the most likely near-term outcome.

This conflict, however, differs from Iraq or Afghanistan in one critical respect. The costs are not borne primarily by the belligerents; they are increasingly borne by the global economy. Every additional month of disruption constrains energy flows, tightens inventories, raises transportation costs, and places upward pressure on inflation. Those costs ripple through households, businesses, governments, and taxpayers.

That is why continuing the campaign is the most likely near-term path, but not a sustainable long-term outcome. As those costs accumulate, the economic and political space to continue the conflict narrows, increasing pressure for negotiation, a maritime settlement, withdrawal—or another strategy that restores stability.

Conclusion

This conflict cannot become another forever war.

The first three options represent strategic choices. The fourth is different. Continuing the campaign may be the most likely near-term path, but every additional month narrows the range of economically and politically viable alternatives.

If policymakers do not impose their own stop loss, the global economy will increasingly impose one for them.

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