**No NATO member has withdrawn from the alliance as of late 2026, and structural, legal, and political barriers make any departure improbable in the near term.** Article 13 of the North Atlantic Treaty requires one year’s notice, while U.S. statute mandates congressional authorization for American exit. Recent U.S. actions under the second Trump administration—such as the withdrawal of approximately 5,000 troops from Germany, a review of European force posture expected by December, and calls for higher allied spending—reflect retrenchment and emphasis on European burden-sharing rather than formal withdrawal. European diplomats express concern that a Republican loss in the November 3 midterms could prompt further troop or funding reductions, yet allies continue to affirm commitment and pursue greater self-reliance through bilateral or EU defense initiatives. Russian demands in Ukraine-related talks for a NATO rollback to 1997 borders remain aspirational and face unified allied resistance. These dynamics sustain low implied probability for any exit by the market’s resolution date.