NATO’s Article 5 collective-defense clause has remained uninvoked since the 2001 response to the 9/11 attacks, with allies consistently opting for Article 4 consultations amid Russia-related airspace and drone incidents. As of mid-2026, no armed attack on alliance territory has occurred, despite ongoing eastern-flank deployments and the 2026 NATO summit’s reaffirmation of deterrence commitments. Recent developments—including a fragile U.S.-Iran ceasefire framework, stabilized Ukraine-Russia front lines, and absence of new hybrid or conventional threats crossing the Article 5 threshold—have reinforced trader consensus that the probability of invocation before the end of 2026 is low. Market pricing reflects this assessment of contained risk through year-end.