NATO’s Steadfast Duel 2026 tests regional defense plans with 8,000 personnel across Europe and U.S.

NATO began Steadfast Duel 2026 on October 6 with approximately 8,000 military and civilian participants distributed across Europe and the United States. The computer-assisted command-post exercise tests the alliance's regional defense plans, concentrating on command coordination, collective defense procedures and the movement of information across geographically separated headquarters. NATO's Joint Warfare Centre supports the activity, involving Allied Command Operations, three Joint Force Commands, component commands and representatives from member nations. Steadfast Duel evaluates planning and headquarters decision-making through a simulated Article 5 scenario; the personnel figure describes exercise participation rather than a corresponding live deployment of combat troops.