Will US withdraw from NATO by 2027?

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Active sub-markets

Market context

The Polymarket contract pricing a U.S. withdrawal from NATO by end-2026 sits at 3% YES, implying traders assign roughly a 1-in-33 chance that the United States will formally initiate exit procedures or lodge official denunciation under Article 13 of the North Atlantic Treaty within the next two years. This probability reflects the institutional weight of NATO membership—a 75-year alliance binding the U.S. to 32 member states through mutual defence obligations—against the political volatility of American leadership transitions and rhetoric around burden-sharing.

Historical precedent offers limited guidance. No NATO member has ever invoked Article 13 to withdraw; the alliance has survived Cold War tensions, disagreements over defence spending, and repeated calls for reform without formal exit. The closest parallel is France's 1966 withdrawal from NATO's integrated military command, though France remained a treaty signatory. Trump's first term (2017–2021) saw sustained criticism of NATO's cost-sharing model and threats of reduced commitment, yet no withdrawal notice materialised. The 2024 U.S. presidential election and subsequent administration's stance on transatlantic security will substantially shape the probability trajectory through 2026.

Traders should monitor statements from the incoming administration regarding NATO funding demands, European defence spending targets, and any formal policy reviews of alliance commitments. Congressional action or judicial challenges could affect implementation timelines but would not prevent YES resolution under the market's terms. Scheduled NATO summits, defence budget negotiations, and any explicit executive orders concerning withdrawal procedures represent key decision points before the December 2026 settlement window closes.

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). The odds column is filled only where we have clean data — that avoids the made-up numbers that get a network demoted when search engines cross-check against the source venue.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Where can I trade this market with the lowest fees?

On Kalshi UK, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Kalshi UK is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does it cost to trade on Kalshi UK?

Zero. Kalshi UK routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.