Will the US Declare War on Iran? Odds & Probability

Markets price the chance of a formal US declaration of war on Iran at 3.6%, making it a long shot.

3.6%+0.4 pts 24h

Will the US officially declare war on Iran by December 31, 2026?

Updated · Volume $7.8M

0%3%5%7%Aug 1Aug 8Aug 16Aug 23Aug 31
OutcomeProbability24h
Will the US officially declare war on Iran by December 31, 2026?3.6%+0.4
Will the US officially declare war on Iran by March 31, 2026?0.0%0.0
Will the US officially declare war on Iran by April 30, 2026?0.0%0.0

The No outcome dominates, and any alternative is seen as even more remote.

Context

The market has and it sits at 3.6% after a +0.4 pts move in the past day

The resolution hinges on a single, narrow condition: Congress must pass a formal declaration of war under Article I, Section 8 of the Constitution, and the president must sign it into law. Authorizations for the Use of Military Force, executive orders, or military actions without such a declaration do not qualify. A clear consensus of credible reporting will determine whether the event occurred. The outcome turns on the deadline of Jan 1, 2027 and the exacting constitutional process. No other event—no speech, no executive action, no escalation short of a congressional vote—settles the market. The resolution source is limited to formal acts of Congress, as verified by trustworthy news outlets.

FAQ

What counts as an official declaration of war?

Only a joint resolution passed by both houses of Congress and signed by the president, consistent with the constitutional power to declare war. No other measure qualifies.

Would an Authorization for the Use of Military Force (AUMF) settle the market to Yes?

No. An AUMF is not a formal declaration of war, and the market explicitly excludes it unless accompanied by a full declaration.

What happens if the US launches a military strike on Iran?

Without a congressional declaration of war, the market would not resolve to Yes. Military action alone is insufficient.

How is the outcome determined?

The market looks for a consensus in credible reporting that Congress has enacted and the president has signed a formal declaration of war by the close date.

Data: Polymarket · Methodology · Not financial advice

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