Simulating Cyber-Resilience: The Strategic Role of the Locked Shields Exercise in Enhancing International Cyber Preparedness

As cyberthreats to critical infrastructure remain prevalent, national response mechanisms must evolve beyond the technical domain to incorporate legal, communicative, strategic, and cross-sector coordination. This work explores Locked Shields, an annual exercise conducted by NATO's Cooperative Cyber Defence Centre of Excellence, as a pedagogical and conceptual framework for simulating whole-of-government responses to cyber incidents. Unlike traditional cyber exercises, Locked Shields engages legal advisors, media strategists, and civil-military roles in realistic, scenario-driven simulations that portray the political and operational conditions of a real international-scale cyber crisis. We detail the exercise architecture, contrast with other cyber exercises, and assess its pedagogical and strategic value. Content analysis from exercise After Action Reports (AARs) from 2021 to 2025, as well as a case study of the structure of a 2025 U.S. Blue Team, we explore the exercise's potential to promote interdisciplinarity learning and facilitate digital government cyber-resilience planning. Both participant surveys data and the case study indicate that Locked Shields is a valuable tool for the enhancement of holistic cyber incident response preparedness at both national and international levels.