The Dragon’s Expanding Sea

China’s creeping conquest of the South China Sea is testing the limits of international law and the resolve of the world’s democracies.

Few lines have caused as much anxiety in the cartographic theatre of our times as the one China insists on drawing across the sea. The “nine-dash line,” an ambiguous crescent looping deep into the South China Sea, transcends the limits of a mere maritime claim. It is Beijing’s geopolitical doctrine and a challenge to the post-war international order.

Strategic Waters

Stretching across waters contested by Vietnam, the Philippines, Malaysia, Brunei and Indonesia, the line encompasses almost the entirety of the South China Sea, one of the world’s busiest maritime arteries through which trillions of dollars in trade pass through it annually. Beneath its waters lie fisheries, hydrocarbons and strategic routes vital to Asia’s economic future. To Beijing, these waters are part of China’s “core interests” - a term also reserved for the sanctities of Tibet, Xinjiang and Taiwan.

China’s justification is steeped in history. Official narratives frequently invoke the Western Han Dynasty and ancient Chinese mariners supposedly traversing these waters as early as the second century BCE. Historical memory, in Beijing’s telling, confers sovereign legitimacy. Yet modern international law is rather less sentimental. Under the United Nations Convention on the Law of the Sea (UNCLOS), maritime rights are governed not by imperial nostalgia but by clearly defined territorial and Exclusive Economic Zone (EEZ) principles.

But that has not restrained Beijing. Over the past two decades China has pursued what strategists call a ‘salami-slicing’ campaign, incremental moves without provoking outright war. Collectively, however, China’s steps amount to a slow-motion redrawing of Asia’s maritime map.

China is increasingly behaving like an archipelagic state akin to Indonesia or the Philippines, claiming rights over waters between island groups as though they were internal seas. Yet UNCLOS recognises only a limited set of nations under such a framework, and China is not among them. Nevertheless, Beijing has persisted in treating contested waters as sovereign space, demanding deference from foreign vessels and aircraft.

More visible has been the transformation of reefs into fortresses. Across the Spratly and Paracel island chains, submerged atolls have been dredged into artificial islands complete with airstrips, radar stations, missile systems and harbours. What were once coral outcrops are now unsinkable military bases. Beijing then uses these engineered features to buttress wider EEZ claims, despite international rulings rejecting such interpretations.

Pressure Tactics

The strategy extends beyond conventional naval power. China has mastered the art of “grey-zone” coercion: pressure tactics deliberately designed to remain below the threshold of war. Instead of deploying destroyers alone, Beijing relies heavily on coast-guard vessels, fishing fleets and maritime militias. Swarms of fishing boats descend upon disputed waters, intimidating rival claimants while providing Beijing plausible deniability.

For smaller Southeast Asian states, the imbalance is stark. Filipino or Vietnamese vessels often find themselves shadowed, blocked or harassed by heavily armed ships of the China Coast Guard. Fishing communities that once operated freely now navigate an increasingly militarised sea.

Beijing’s most audacious manoeuvre, however, has been juridical. China routinely twists the language of UNCLOS to justify claims that the treaty itself plainly undermines. In 2016, the Permanent Court of Arbitration in The Hague delivered a sweeping rebuke, ruling that China’s expansive ‘historic rights’ claims had no legal basis under international law. The tribunal also determined that several contested features in the Spratly Islands were incapable of generating full EEZ entitlements.

China has simply ignored the verdict. Western powers, led by the United States, have attempted to challenge Beijing through Freedom of Navigation Operations (FONOPS), sailing naval vessels through disputed waters to demonstrate that these are international seas, not Chinese lakes. Yet such symbolic missions are sorely limited in efficacy.

Many analysts increasingly argue that occasional naval patrols and ritual diplomatic protests are insufficient against a power willing to combine patience, economic leverage and military intimidation. While China’s strategy is cumulative and long-term, the response to it often appears episodic and reactive.

Nor is Washington’s position entirely uncomplicated. America champions UNCLOS while never having ratified the convention itself, a contradiction Beijing has eagerly exploited. Meanwhile, perceptions of declining American resolve, heightened by Middle Eastern entanglements, domestic political polarisation and wavering strategic consistency, have emboldened Chinese assertiveness. The QUAD grouping of India, Japan, Australia and America has yet to evolve into the cohesive strategic bloc many once imagined.

India, too, occupies an increasingly pivotal role in this maritime contest. Though not a claimant in the South China Sea disputes, it has deep stakes in preserving freedom of navigation and resisting any precedent that allows powerful states to unilaterally redefine maritime norms. Beijing’s ambitions no longer stop at the ‘near seas.’ Through ports, infrastructure projects and naval deployments stretching from Gwadar to Djibouti, China is steadily expanding its footprint into the Indian Ocean and the wider Indo-Pacific.

If Beijing succeeds in normalising its expansive interpretation of maritime sovereignty, other revisionist powers may follow suit. The result would not merely be regional instability but the erosion of the very rules underpinning global commerce and navigation.

The South China Sea has thus become a laboratory for a new kind of geopolitical contest being fought through attrition and incremental encroachment. China’s genius lies in understanding that global attention spans are short, democracies divided and institutions slow-moving.

That leaves the international community with an uncomfortable choice. Either it collectively reinforces the legal norms embodied in UNCLOS and the Hague ruling, or it tacitly accepts a world in which might quietly supersedes right.

(The author is a retired naval aviation officer and a defence and geopolitical analyst. Views personal.)