NATO’s Supreme Headquarters Allied Powers Europe (SHAPE) in Mons, Belgium, and Allied Command Operations (ACO) successfully concluded Exercise STEADFAST DUEL 2026 today, demonstrating Allied Command Operations’ ability to turn NATO’s plans into action, execute NATO’s deterrence and defence plans, and command and control multi-domain operations across the Alliance. 

Over ten days of demanding training, approximately 8,000 military and civilian personnel, supported by all 32 Allied nations, exercised across multiple locations in Europe and the North America. STEADFAST DUEL 2026 tested the execution of plans under NATO’s Concept for Deterrence and Defence of the Euro-Atlantic Area (DDA). With a primary focus on NATO’s Northwest region, including parts of the Arctic, the exercise challenged NATO headquarters to coordinate activities across commands, nations and domains, strengthening the warfighting readiness required to deliver credible deterrence and defence across the Euro-Atlantic area. STEADFAST DUEL 2026 successfully tested NATO’s command-and-control structures and the ability of Allied headquarters to work together at scale and speed. Operating in a 24/7 exercise environment, participants trained across the land, air, maritime, space and cyberspace domains, combining NATO’s fight tonight readiness with preparation for future challenges. The exercise also provided an opportunity to identify lessons, refine processes and further strengthen interoperability across the Alliance.

“Our plans are only as strong as our ability to execute them,” said General Alexus G. Grynkewich, Supreme Allied Commander Europe. “STEADFAST DUEL evaluated our command and control, strengthened interoperability across the Alliance, and built the warfighting readiness we need to deliver credible deterrence and defence across the Euro-Atlantic area.”

From planning to execution

STEADFAST DUEL 2026 marked a key step in NATO’s broader 2026 exercise campaign. Earlier this year, Exercise STEADFAST DETERRENCE 2026 (STDC26) brought together all 32 NATO nations and, for the first time, all ACO headquarters. STEADFAST DUEL built on that work by executing the plans activated during STDC26, further strengthening NATO’s ability to translate strategic planning into effective action across the Alliance.

“Steadfast Duel is about turning our plans into action,” said General Alexus G. Grynkewich, Supreme Allied Commander Europe. “By training together across commands, nations and domains, we strengthen our ability to fight as one Alliance and test our warfighting readiness, deter aggression and defend every Ally.”

Together, the exercises provided a progressive framework for NATO to test and refine the transition from strategic planning to operational execution. STEADFAST DUEL exercised the broader DDA family of plans in a demanding simulated conflict environment, testing NATO’s ability to conduct large-scale, multi-domain operations as one Alliance.

Integrating advanced digital capabilities

STEADFAST DUEL 2026 also further integrated advanced digital capabilities into the exercise environment. The NATO Maven Smart System (N-MSS) expanded connectivity across systems and commands throughout Allied Command Operations. During the exercise, N-MSS exchanged data with the U.S. instance of Maven Smart System, enabling information to flow in both directions. By fusing data from NATO and Allied systems, exercise participants had access to a real-time Recognized Ground Picture, combining multiple layers of information and strengthening shared situational awareness across participating headquarters. Using live-data integrations and shared operational pictures, these capabilities were vertically aligned between the Joint Force Commands, Joint Support and Enabling Command, Domain Commands and SHAPE, helping commanders understand the theatre-wide status of supplies and available support while anticipating future operational demands. Additionally, a decision support tool was utilized to assist with bringing pertinent information to commanders attention ahead of Decision Points as laid out in our plans. The use of N-MSS during STEADFAST DUEL also contributed to NATO’s wider AI in audacious training initiative, demonstrating how AI-enabled and digital capabilities can support increasingly complex training, readiness and warfighting effectiveness. 

Turning lessons into stronger collective action

The conclusion of STEADFAST DUEL does not mark the end of the process. Lessons identified throughout the exercise will now be analysed and incorporated into future planning and training to refine procedures and support the Alliance’s continued adaptation to an evolving security environment. Exercises such as STEADFAST DUEL allow NATO to challenge its headquarters, plans and procedures against complex and demanding scenarios. They improve coordination among Allies and commands, strengthen interoperability across domains and contribute to faster and more coherent execution of Alliance plans. By successfully completing STEADFAST DUEL 2026, NATO has taken another step in strengthening its ability to plan, act and adapt collectively, reinforcing the warfighting readiness required to fight tonight, prepare for tomorrow, deter aggression and defend every Ally.

SHAPE is the military headquarters of ACO.

For more information, visit www.nato.int or https://shape.nato.int/.

Story by SHAPE Public Affairs Office