Today’s most consequential battles are no longer confined to traditional warfare settings. Instead, actors increasingly rely on hybrid warfare tactics, including cyber operations, disinformation campaigns, covert actions, and economic pressure to achieve strategic objectives. By employing these unconventional tactics, actors deliberately exploit the grey zone - an area that exceeds normal peacetime relations but remains below the legal threshold for the use of force. Since the end of World War II, the grey zone has grown alongside the rapid expansion of international law and technological advances, altering traditional methods of interaction between states. Although the grey zone challenges the scope and perceived relevance of international law, it also underscores a strength of the system: its capacity to adapt to a dynamic and evolving global order.
In recent decades, international legal institutions have sought to add clarity to international law. After World War II, the UN Charter codified when force could and could not be used. Article 2(4) is the central provision prohibiting UN member states from using force against the territorial integrity or political independence of any state. However, Chapter VII recognizes the need for force in certain situations and develops the legal basis for the UN Security Council to authorize action. Article 51 then permits the use of force that is both necessary and proportionate in order to uphold the inherent right of individual or collective self-defense. Overall, these provisions seek to safeguard international peace and security by narrowly defining exceptions to the general prohibition on the use of force.
While international law draws a firm boundary around the use of force, it remains relatively silent on actions that do not meet this threshold. Because international law draws a sharp distinction between armed force and non-forceful conduct, it leaves room for actors to engage in coercive behavior that exceeds normal peacetime competition without crossing the line into legally recognized armed conflict. It is within this space of legal ambiguity that hybrid warfare tactics have flourished. In this way, the international legal system reflects a complicated paradox that simultaneously promotes security while creating the capacity for actors to operate along its margins.
Ongoing tensions between China and Taiwan exemplify how such hybrid warfare tactics can undermine an adversary. In 2023, the Matsu Islands lost internet connectivity for several weeks after an underwater telecommunications cable was severed, an incident that the Taiwanese government blamed on China. In 2025, Taiwan again accused China of disrupting the submarine Trans-Pacific Express Cable System. Such actions disrupted civilian life and economic activity while creating strategic ambiguity. More importantly, these attacks indicate that China felt compelled to act within the grey zone. In other words, China implicitly acknowledged the relevance of the international legal system by conforming to the bounds of international law. Furthermore, China employed disinformation campaigns including AI-generated stories and deepfakes (media that is altered to make someone appear to say something they never actually did) to successfully influence the outcome of Taiwan’s 2024 elections. This striking ability to shape Taiwanese political processes and public life without using any force has exacerbated existing tensions and transformed China-Taiwan relations into a condition of coercion, aggression, and deception that targets Taiwan’s strategic autonomy without triggering formal conflict. Most importantly, by operating in the grey zone, China acknowledges the legal boundaries to which it must adhere, thus reflecting the continued relevance of international law.
Furthermore, the Russia-Ukraine conflict demonstrates how hybrid warfare techniques can operate alongside conventional military operations in an active war setting. Following the 2022 invasion, Russia increasingly integrated grey zone tactics such as disinformation campaigns, information suppression, and attempts to control digital infrastructure into its conventional military operations. Efforts to sever internet and mobile connectivity, combined with persistent narratives framing the invasion as “denazification” or genocide prevention, sought to weaken Ukrainian morale, confuse Western audiences, and influence global opinion. This blending of conventional force with grey zone activities illustrates how hybrid warfare can amplify military objectives while complicating legal accountability. By operating along the peripheries of international legal structures and normalizing low-intensity coercion as a tool of global competition, Russia illustrates how hybrid warfare is reshaping both international law and global power dynamics.
While many claim that the ambiguity found in grey-zone conflict is a weakness of the international legal system, it is actually a necessary feature of its continued relevance. International law was never designed to freeze conflict within a particular historical frame. Instead, it provides a foundation capable of adapting to new technologies, tactics, and strategic realities. As cyber capabilities, information warfare, and economic interdependence continue to reshape international relations, legal ambiguity allows competing interests to coexist, functioning as a mechanism that places checks on the unilateral exercise of power. In this way, the grey zone reflects an adaptive legal order that constrains unchecked power while enabling actors to respond to a dynamic global landscape.
Ultimately, the existence of grey zone conflicts indicates that states acknowledge legal thresholds and legitimacy. Moreover, by operating within the grey zone, laws governing the use of force achieve precisely what they were designed to do: limit the violent resolution of conflicts. While the grey zone offers the space for actors to advance strategic objectives, its adaptive capacity also enables the international community to respond to novel threats and unchecked exercises of power. The very existence of grey-zone tactics therefore underscores legal legitimacy in international relations. Rather than signaling the failure of international law, grey-zone conflict demonstrates how deeply embedded it remains in the decision-making process and power dynamics.
By Luke Wolfe, WACNH Intern
