NATO has invoked Article 5 only once in its history, after the 2001 attacks, and recent incidents such as Russian drone incursions into Poland in 2025 prompted only Article 4 consultations and enhanced eastern flank measures like Operation Eastern Sentry. As of mid-2026, ongoing Russia-Ukraine hostilities and hybrid threats have not produced an armed attack on alliance territory, while NATO summits have focused on reaffirming collective defense commitments, increasing defense spending, and bolstering deterrence without signs of imminent escalation to the Article 5 threshold. Traders assign a 93.5% implied probability to no invocation before 2027 because current geopolitical dynamics favor continued sub-threshold activity and alliance preparedness over rapid direct confrontation.