NATO’s Article 5 collective-defense clause has been invoked only once in its history, after the 2001 attacks, establishing a high evidentiary threshold for an “armed attack” that would trigger consensus among all 32 allies. Recent developments reinforce trader expectations of no invocation before 2027: Russia remains heavily committed to operations in Ukraine with limited capacity for a new front against NATO territory, while incidents such as Iranian missile activity near Turkey in early 2026 prompted explicit statements from NATO Secretary General Mark Rutte that Article 5 was not under discussion. Ongoing hybrid threats and Russian diplomatic warnings of rising risks have not produced qualifying attacks or alliance-wide consensus for activation. NATO’s enhanced forward presence on the eastern flank and continued deterrence posture further reduce near-term triggers, aligning with the 88.5% implied probability on “No.”