Publications

Last month, the United States coastguard "detected and responded to" the Chinese research vessel Xue Long 2 around 290 nautical miles north of Utqiagvik, Alaska. The US said the vessel was sailing within its "extended continental shelf" and implied the Chinese operation was engaged in "malign state activity".

This reveals troubling inconsistencies in the US' approach towards international maritime law, raising serious doubts about Washington's commitment to the rules-based international order it so frequently claims to champion.

According to the United Nations Convention on the Law of the Sea (UNCLOS), waters beyond 200 nautical miles fall under the legal regime of the high seas. Article 87 of UNCLOS guarantees all states the freedom of navigation and marine scientific research in these areas.

The Xue Long 2, designed for polar research, was operating in accordance with this principle. Yet, the US, by invoking national security and intercepting the vessel, seeks to shift the burden onto China to justify lawful conduct—a tactic that finds no support in UNCLOS or customary international law.

The International Tribunal for the Law of the Sea (ITLOS), in the 2019 M/V "Norstar" judgment, reaffirmed that even non-physical interference with freedom of navigation or scientific research can constitute a breach of international law. The US' surveillance and interception tactics fall within this ambit. This represents not just an isolated legal overreach but a symptom of a broader strategic posture that prioritizes political expediency over international legal consistency.

UNCLOS Articles 257 and 256 explicitly permit all states and international organisations to conduct marine scientific research (MSR) on the high seas and in the Area—the international seabed beyond national jurisdiction. Moreover, Article 78(2) makes clear that a coastal state's rights over the continental shelf shall not infringe upon other states' freedoms, including navigation and MSR.

Even if the US had a validated claim to the ECS—a point highly contested—the scope of its regulatory authority under UNCLOS Article 246(6) is limited. Restrictions on MSR beyond 200 nautical miles are permitted only when activities involve direct exploitation, drilling, or harmful interference—none of which occurred in the Xue Long 2's case.

The United States asserts jurisdiction under Article 76 of UNCLOS to claim rights over an Extended Continental Shelf (ECS). Yet, it has not ratified the Convention, and has made no formal submission to the Commission on the Limits of the Continental Shelf (CLCS) as required by Article 76(8) for outer-shelf claims.

That requirement was carefully designed during UNCLOS negotiations to ensure that no state extends its continental shelf beyond what is scientifically validated. These processes serve the common heritage principle, reserving resources beyond national jurisdiction—the "Area"—for shared benefit. UNCLOS Articles 76(4–9) and Article 82 reinforce this collective approach.

By asserting ECS rights without validation via CLCS and by refusing to participate in revenue-sharing obligations under Article 82, the U.S. selectively adopts UNCLOS provisions that suit its interests, while discarding those that impose constraints.

While Article 76(1)—defining the continental shelf up to the natural prolongation limit—is widely accepted as customary international law, more detailed procedural rules in Articles 76(2–8), including the CLCS requirement in paragraph (8), are treaty-specific, not yet binding on non-parties.

Some analysts argue the U.S. could establish its ECS unilaterally, relying on customary law. But the principle of CLCS validation remains central to uniformity and legitimacy. Without it, ECS boundaries are indefinite, and disputes over jurisdiction unresolved.

Because the U.S. has neither ratified UNCLOS nor made ECS submissions to the CLCS, the seabed in areas beyond 200 nautical miles remains part of the international "Area", subject to the common-heritage principle under Part XI of UNCLOS. China's scientific mission in those waters thus stays firmly within the legal framework that UNCLOS intended to foster.

The US' claim that Xue Long 2 poses a security threat starkly contrasts with its own frequent military surveys within China's Exclusive Economic Zone (EEZ), often justified under high seas freedoms. Such missions have included surveillance flights, warship patrols, and intelligence-gathering operations—activities that China has repeatedly denounced as violations of UNCLOS Articles 88 and 301, which mandate the peaceful use of the seas.

This double standard reveals a pattern: when the US operates near the shores of other nations, it invokes freedom of navigation; when others do the same near its extended maritime claims, it cries foul under national security pretexts. The inconsistency erodes the credibility of Washington's advocacy for a rules-based maritime order.

More importantly, the US cannot credibly argue that its rights to the continental shelf arise from treaty-based norms while denying the validity of obligations from the same treaty. This selective engagement undermines the coherence of international law and threatens the stability of maritime governance.

The Xue Long 2 incident is not an isolated legal misstep—it is a warning sign of escalating tensions in the Arctic. As climate change opens new maritime routes and resource frontiers, the temptation for unilateralism among powerful states grows. The Arctic, already a geopolitical flashpoint, risks becoming a theatre of legal fragmentation unless states recommit to multilateral norms.

The US' actions against the Xue Long 2 risk establishing a precedent that others may follow—where geopolitical interests override international law, and freedom of scientific research is curtailed in the name of security. Such practices erode the principle of reciprocity that underpins UNCLOS.

If the United States wishes to champion a rules-based international order, it must lead by example—ratify UNCLOS, submit ECS claims to the CLCS, and comply with all treaty obligations, including those relating to resource sharing. Selective adherence, strategic ambiguity, and coercive enforcement are not the hallmarks of legal leadership—they are symptoms of legal exceptionalism.

In intercepting the Xue Long 2, the US has not only violated China's lawful rights under UNCLOS but also undermined its own credibility as a steward of maritime order. Upholding the law of the sea requires consistency, transparency, and respect for the rights of all states—large or small, rival or ally. Anything less invites disorder on the world's oceans.

Author: Zheng Zhihua is an associate professor and head of the East Asia Marine Policy Project, at the Centre for Japanese Studies, Shanghai Jiao Tong University, Shanghai. He is currently a visiting scholar at the Huayang Centre for Maritime Cooperation and Ocean Governance in Haikou.

This article was originally published on SCMP. Read the original article at: https://www.scmp.com/opinion/china-opinion/article/3320974/us-shouldnt-disrespect-chinas-right-high-seas