Will US withdraw from NATO by... Odds & Analysis
What the market is pricing and why direction matters more than level
The will US leave NATO odds have fallen to their lowest level since the market opened. As of late October 2026, the main contract, which asks whether the United States formally initiates withdrawal or files an Article 13 notice of denunciation by December 31, 2026, trades at about 1.6% Yes and 98.4% No, with a bid of 1.5 cents and an ask of 1.7 cents. The event has drawn roughly $6.4 million in volume across its four deadline contracts, and the April 30, June 30 and August 31 versions have all already resolved No. PredMart lets traders take leveraged positions on this market, but the more useful starting point is the price history and the roughly ten weeks of catalysts left before the deadline.
The trend is clear. The contract opened near 10% in November 2025, spiked to about 18.5% in late January during the Greenland standoff, sat at 4-6% in February, climbed back into the low teens in April when the administration openly weighed an exit after the Iran war, then bled out to around 5% by mid-June. Since the Ankara summit in early July it has ground lower almost every week: around 3% in late July, 2-2.5% through September, a brief bump to 2.75% in early October, and 1.6% now.
The real question is no longer whether withdrawal is likely, since the market puts it at well under 1 in 50. What is left to price is whether anything can force a formal notice in the roughly 68 days before December 31, and whether 1.6% fairly prices that tail.
The front-runner: why No sits at 98%
The No side at 98.4% rests on law more than on rhetoric. The 2023 statute in the FY2024 defense bill bars a president from suspending, terminating, denouncing or withdrawing from the North Atlantic Treaty without the advice and consent of two-thirds of the Senate or an Act of Congress. A February 2026 Congressional Research Service report (R48868) went through those limits in detail, and nothing passed since has loosened them. A legislative exit would need 60 Senate votes, and Senator Mike Lee's withdrawal bill never came close.
Congress has also been adding barriers rather than removing them. The FY2026 defense authorization, signed into law, set a floor of 76,000 US personnel in Europe, according to Berliner Zeitung's coverage of the signing. In May, Stars and Stripes reported that the House draft of the FY2027 bill (H.R. 8800) renews that floor and adds a requirement that the Pentagon first assess moving troops to NATO's eastern flank before bringing them home. Republican Armed Services chairs Roger Wicker and Mike Rogers publicly criticized the May troop cut in Germany. That is a sign that support for the alliance on Capitol Hill crosses party lines.
One detail in the resolution rules keeps this from being a pure legal call. The contract resolves Yes if the US "formally initiates" withdrawal or delivers an Article 13 notice, "regardless of if its implementation is immediately halted or delayed by judicial or other actions." The statute does not stop the outcome the contract measures. It makes that outcome a deliberate act of defiance with a guaranteed court fight. The residual 1.6% is the price of that defiance scenario, not of a lawful exit. The rules also exclude leaving NATO's integrated military command, so a France-1966 style partial pullback would not count.
The biggest mover: what the 2026 swings actually showed
This contract has had two real spikes, and both faded without any procedural follow-through. The first came in late January, when the Greenland dispute pushed Yes to about 18.5% before a framework understanding with Secretary-General Mark Rutte cooled it back to around 5% within two weeks. The second followed the start of the Iran war on February 28. On April 1, Reuters, citing a Telegraph interview, reported that Trump said he was strongly considering an exit after allies declined to support operations against Iran and to help reopen the Strait of Hormuz. He called NATO a "paper tiger." Al Jazeera reported on April 8 that the administration was openly mulling withdrawal, and Yes traded in the low teens through late April.
What followed was a downgrade in form, not a withdrawal. In early May the Pentagon ordered about 5,000 troops out of Germany, roughly 14% of the US presence there, after a public dispute with Chancellor Friedrich Merz. An Army brigade rotation to Poland was suspended, and on June 18 the Defense Department opened a six-month review of US force posture and basing in Europe. The market read each step correctly: the administration was cutting its footprint in Europe while keeping treaty membership, and Yes drifted from about 9% in late May to 5% by mid-June.
The lesson for pricing is that rhetoric moved the contract and posture changes did not. Spikes came on words ("strongly considering," "reevaluating"), and every one of them gave back its gains once no notice was filed. A trader who treats the next headline as a volatility event rather than a regime change has been right every time this year. The one exception would be a headline that comes with a document attached.
Rest of the field: where the cheap contracts hide
Reading the US-exit contract next to the rest of the NATO complex is the best check on whether 1.6% is mispriced. As of late October 2026:
- Will any country leave NATO by December 31, 2026: about 4.8% Yes. This is three times the US-specific price, which implies traders see a non-US exit as more likely than a US one. It is also a reminder that thin long-dated contracts often carry a premium of a few points above any modeled probability.
- NATO dissolves before 2027: about 1.3% Yes. Dissolution almost certainly requires a US exit first, so it should trade at or below the US contract, and it does. The 0.3-point gap is narrow, which suggests both contracts mostly reflect a floor of illiquidity and tail premium rather than distinct views.
- NATO Article 5 invoked before 2027: about 4.95% Yes, and a NATO-Russia military clash by December 31 at about 18.5%. Those numbers price real stress on the eastern flank, but stress there has historically pulled Washington toward the alliance, not away from it.
- Ukraine joins NATO before 2027: about 1.4% Yes. The Economist reported on a new US peace proposal (summarized by Ukraine Today on October 23) under which Kyiv could forgo NATO membership in exchange for investment and an EU track, which keeps that contract pinned.
The resolved contracts tell the same story. The April 30 deadline closed No after more than $4 million in volume despite the peak of the Iran-war rhetoric. The June 30 and August 31 deadlines also closed No. The summit-attendance market resolved Yes for Trump and Secretary of State Marco Rubio and No for Vice President JD Vance. Each deadline that passed without a notice took a step out of the December contract's price.
The Ankara summit and what changed since June
The July 7-8 summit in Ankara was the event the market had been waiting on, and it removed most of the remaining risk. Trump attended, and the United States signed onto a consensus declaration whose opening paragraph reaffirmed an "ironclad commitment" to collective defense under Article 5. Post-summit analyses highlighted three outcomes. Allies backed the Hague pledge of 5% of GDP by 2035 with about $50 billion in newly announced procurements. Ukraine received commitments of nearly 70 billion euros in military equipment, assistance and training. And the declaration stated that European allies and Canada are assuming greater responsibility for the alliance's defense. The friction came from Trump's remarks on Greenland, Iran and Spain, including his complaint that allies had not backed the US campaign against Iran.
The Yes price fell from about 4.6% at the start of July to about 3% two weeks after the summit. It has not closed a week above 3.3% since.
The autumn has brought a different kind of pressure: selective engagement rather than exit. Euronews reported on October 5 that the Pentagon's "Bergen Group" format, convened under Under Secretary Elbridge Colby with Norway, Sweden, Finland, Poland, Germany and the Netherlands, held a meeting in Poland that left out the UK, France and the Baltic states. Allies called it divisive. But the format assumes the US stays inside NATO and reshapes it from within, and that is the opposite of a denunciation notice. The early-October bump to 2.75% came during this stretch and faded within a week.
Catalysts: what is left before December 31
Only a few dated events remain that could plausibly force a formal notice:
- November 3, 2026 midterms. A Democratic House or Senate would make any challenge to the 2023 statute even less likely and would raise the political cost of a defiant notice. A strong Republican showing would not change the statute either, because repealing it still needs 60 Senate votes. In either case the election matters more for the 2027 debate than for this contract. Some European commentary, such as Modern Diplomacy on October 22, argues that a weakened administration could push allies to take a harder line, which would raise the rhetorical temperature without creating a legal path.
- FY2027 NDAA conference, November-December. The House bill renews the 76,000-troop floor in Europe. If the final text keeps that provision or something close to it, Congress will have restated its constraints on the eve of the deadline. Dropping it would be a meaningful negative signal, but it would still not count as withdrawal.
- Mid-December: the Pentagon's European posture review. The six-month review opened on June 18, so its findings are due around mid-December. Deeper troop cuts are the most likely headline from that review. Based on the May Germany cut, the market should treat that as a posture story, not a treaty story, although a sharp drawdown announcement could produce a short-lived spike.
- Early December NATO foreign ministers' meeting. Ministers usually meet in Brussels in the first week of December. A Rubio no-show or an openly hostile message would be the most direct near-term rhetorical risk.
- December 31, 11:59 PM ET resolution. With no notice filed, time decay takes the price toward zero over the final weeks, as happened with the June 30 and August 31 contracts.
Bottom line: the setup and where PredMart fits
With about 68 days left, the market is pricing a formal US withdrawal notice in 2026 at roughly 1.6%, near the bottom of its 12-month range of 1.6% to 18.5%. That price looks defensible. The 2023 statute, Congress's troop floor and the Ankara declaration all point the same way. The administration's real pressure on Europe, through troop cuts, the posture review and the Bergen Group, has come as a downgrade from within the alliance rather than an exit. And every 2026 spike faded without a document being filed. Yes is not zero only because the contract counts a defiant notice even if courts later block it. A president who has repeatedly called leaving an option keeps that tail alive.
The asymmetry runs both ways. At 98.4 cents, No has at most about 1.6 cents of upside to resolution. A headline spike like January's or April's would take several points off that. With leverage, that kind of mark-to-market drawdown is what gets a position liquidated before the thesis plays out. Yes at 1.6 cents is a cheap but steadily decaying hedge against the defiance scenario. The posture review in mid-December is the most likely source of the year's last volatility.
For traders who want to act on that view with more capital efficiency, PredMart offers leveraged exposure to this event. Size it with the January and April drawdowns in mind.
Trade with up to 4x leverage: predmart.com/event/will-us-withdraw-from-nato-before-2027