Grey Zone Conflict in the Indo-Pacific: Taiwan, Cyber Threats, and Maritime Lawfare

Author: Jordan Rinaldi

The Indo-Pacific has become the world’s most contested maritime region, where great-power rivalry, technological warfare, and legal manipulation intertwine in what experts call grey zone conflict. These are actions deliberately calibrated to stay below the threshold of open war, exploiting ambiguity to advance political and military objectives without triggering confrontation. Nowhere is this more visible than in China’s campaign to reshape the regional order, especially around Taiwan and the South China Sea.

Photo source: The Guardian, South China Sea: Beijing Begins Military Drills Ahead of Key Territorial Ruling, Tom Phillips

Grey zone operations are not new, but Beijing has refined them into a sophisticated toolkit that merges cyber operations, maritime coercion, and lawfare. In the case of Taiwan, this appears to be a constant drumbeat of online disinformation operations, airspace violations, Chinese coast guard patrols, and intimidation, aimed at wearing down the island's defences, and normalizing Chinese presence on its outskirts. Taiwan's allies are confused about how or when to react as a result of these strategies, which conflate peace with conflict.

China's "maritime militia," which are supposedly civilian fishing boats under the command of the People's Liberation Army Navy, are crucial at sea. Under the pretense of lawful fishing, these boats physically block rival claimants, swarm disputed reefs and shoals, and assist Beijing in establishing authority over disputed areas without firing a shot. In the South China Sea, these operations have pushed the boundaries of international maritime law and tested how far rules-based norms can stretch before they break.

This “maritime lawfare” strategy, using legal arguments as a weapon of policy, has allowed China to reinterpret the United Nations Convention on the Law of the Sea (UNCLOS) to justify expansive sovereignty claims, such as the infamous “nine-dash line.” Despite the 2016 Hague Tribunal ruling that invalidated these claims, Beijing continues to build artificial islands, establish military bases, and enforce exclusion zones. The goal is clear: to create new legal and territorial facts on the water faster than international institutions can react.

Meanwhile, the cyber dimension adds another invisible layer. Taiwan experiences daily cyberattacks traced to mainland China, targeting government networks, infrastructure, and public opinion. These digital incursions, often aimed at undermining trust in democratic institutions, spread disinformation to fracture social cohesion. When combined with military drills and diplomatic isolation, cyber warfare becomes an essential tool in China’s grey zone arsenal, eroding resistance from within.

Countering these strategies is a strategic challenge for Western and regional nations. Grey zone operations take advantage of political and legal hesitancy, with each provocation being too small to warrant a full-scale military reaction. More than just weaponry is needed for deterrence in the grey zone; coordination, resilience, and trustworthy signalling are all necessary. While Taiwan is making significant investments in asymmetric capabilities, small, mobile forces intended to thwart large-scale coercion, the United States, Japan, and Australia have expanded joint drills and surveillance in the area.

Yet, the long-term contest may be one of endurance rather than escalation. China’s grey zone strategy thrives on slow, cumulative gains, the normalization of control. Preserving stability in the Indo-Pacific will depend on how effectively democratic states can defend not only their territory, but also the rules that govern it. In an era where conflict is waged in the shadows, the greatest challenge is not knowing where the line is drawn until it’s already been crossed.