NATO Allies Need a Plan for Addressing Threats Below the Threshold of War

Why It Matters

Without a unified NATO strategy, individual states bear the full cost of defending against increasingly sophisticated gray‑zone attacks, risking security gaps across Europe.

Key Takeaways

• NATO lacks a formal role for subthreshold gray‑zone attacks.
• Gray‑zone tactics now include telecom sabotage, water‑plant intrusions, weaponized migration.
• Nordic, Baltic, and UK states lead proactive resilience measures.
• Ankara summit could designate NATO as a coordination hub for gray‑zone response.
• Members ignoring gray‑zone threats may receive no assistance if attacked.

Pulse Analysis

Gray‑zone aggression has evolved from simple disinformation and cyber‑espionage to a broad spectrum of low‑intensity attacks that target critical infrastructure, migration flows, and public safety. Over the past five years, European nations have seen telecom masts cut, water‑treatment facilities breached, and drones disrupt airports—all traced back to state actors seeking strategic advantage without triggering Article 5. This shift reflects a strategic calculus where adversaries exploit the alliance’s collective‑defense threshold, forcing policymakers to reconsider how security is defined beyond conventional warfare.

NATO’s founding treaty binds members only to respond to an armed attack, leaving a doctrinal vacuum for subthreshold threats. While the alliance has facilitated information sharing and best‑practice workshops, it has never adopted a formal response mechanism for gray‑zone incidents. The 2023 Vilnius summit hinted at a role for “hybrid attacks,” yet concrete operational guidance remains absent. As the alliance grapples with budgetary pressures, the Ukraine conflict, and divergent threat perceptions, establishing a dedicated coordination hub could reconcile these challenges by providing a non‑escalatory platform for joint planning, resource pooling, and rapid decision‑making.

The Ankara summit offers a decisive moment to codify this hub, turning NATO into a convener rather than a direct combatant in gray‑zone scenarios. By institutionalizing shared response options—such as joint cyber‑defense exercises, coordinated infrastructure hardening, and rapid diplomatic signaling—NATO can enhance collective resilience while preserving its core military mandate. Successful implementation would signal to adversaries that even low‑level aggression carries coordinated costs, thereby strengthening European security architecture and reinforcing alliance solidarity in an increasingly ambiguous threat environment.