Nov 5 2025

NATO’s largest communications and information systems interoperability exercise concludes

From 6 October to 7 November 2025, the second execution phase of Exercise Steadfast Cobalt is taking place across Europe, concluding the annual exercise.

As NATO’s largest Communications and Information Systems (CIS) interoperability exercise, Steadfast Cobalt brings together approximately 750 participants from 12 Allied Nations and 36 NATO entities. The shared mission is to verify, validate and enhance the interoperability of integrated static and deployable CIS systems and services, strengthening NATO’s readiness and operational efficiency.

Building on the infrastructure established in phase one of the exercise, this iteration continues to expand the mission network, enabling forces to operate together, at any moment. This two-phased format represents the most complex iteration of the exercise to date.

NATO’s largest communications and information systems interoperability exercise concludes

More than 300 personnel from the NATO Communications and Information Agency (NCIA) are supporting the execution of Steadfast Cobalt 25 to ensure seamless connectivity and communication between participants. NCIA provides the fundamental foundations for the mission network, and acts as a facilitator as the overall federated CIS technical design authority. This includes supporting operational requirements, establishing interoperability tests, performing technical evaluations and providing configuration tools.

Through contributions from NATO and the Allies and in collaboration with the NATO CIS Group (NCISG), seamless end-to-end federated services are established collectively across the network federation for the multinational user community. These services are supported by both static and deployed infrastructure, which is monitored 24/7 and protected by around the clock cyber services.

"The national forces who have contributed with their CIS equipment to the mission network have worked hard to comply with the latest technical specification from the NATO-led Federated Mission Networking Initiative,” explains Nicholas Lambert, Principal Enterprise Architect in NCIA’s Chief Technology Office. “This enables the successful federation of national services and capabilities with those of the NATO Command Structure, strengthening the Alliance’s interoperability and ability to respond rapidly in a crisis."

The scale and scope of Steadfast Cobalt 2025 underscores NATO’s prioritization of strengthening CIS defence capabilities across the Alliance, so that Nations stand ready to operate together with efficiency. NCIA remains committed to working with Allies to support NATO’s mission readiness, by training and strengthening CIS skills and capabilities required to combat increasingly complex security threats.