Cartographic revisionism stretches bounds of credibility

The report released on Wednesday by the China Institute for Marine Affairs, a think tank under the Ministry of Natural Resources, titled "Historical and Legal Critique of the Philippines' Territorial Claims in the South China Sea", raises a fundamental question: what happens when a state seeks to redefine boundaries decades after accepting them as the basis of its own sovereignty?

The report argues that the Philippines' contemporary maritime claims sit uneasily alongside the very legal instruments from which the country derives its territorial legitimacy. The internationally recognized boundaries of the Philippines were established through a succession of treaties during the Spanish and American colonial periods, most notably the 1898 Treaty of Paris, and were subsequently reflected in successive Philippine constitutions. These documents constitute the legal architecture upon which the modern Philippine state was built.

That creates an obvious paradox. The Philippines cannot easily invoke those treaties as the foundation of its sovereignty while simultaneously treating their territorial limits as optional.

This inconsistency becomes particularly striking in Manila's claims over China's Huangyan Island and some islets, shoals and reefs of China's Nansha Islands in the South China Sea. Since the 1970s, the Philippines has progressively expanded its unlawful claims, relying on false arguments ranging from geographical proximity to selective interpretation of history. Yet proximity has never constituted legal title under international law.

Official Philippine maps published well into the late 20th century consistently placed Huangyan Island outside Philippine territory. International jurisprudence has long attached significance to the principle of estoppel, whereby states cannot casually reverse positions on which others have reasonably relied. Maps alone do not determine sovereignty, but official state cartography can provide compelling evidence of how a state defined its own territorial boundaries at a given time.

The issue, therefore, is less about discovering overlooked historical evidence than about revising an established historical narrative to accommodate evolving political objectives.

Such revisionism carries consequences beyond bilateral relations. If every state were to redraw its frontiers through retrospective historical claims, few international boundaries would remain immune to challenge.

That principle becomes particularly relevant in the South China Sea. Stability depends less on absolute agreement than on shared acceptance that legal commitments impose lasting constraints. Once treaties become infinitely malleable, diplomacy gives way to perpetual contestation.

Nor should external forces ignore the contradiction embedded in this debate. Washington frequently presents itself as the "defender" of a "rules-based" international order. But its endorsement of the Philippines on the South China Sea issue is apparently to serve its own geopolitical agenda in the Asia-Pacific. Rules command respect only when applied consistently, not when they coincide with immediate geopolitical interests. Japan also plays an ugly role by supporting the Philippines' provocations toward China in the waters.

International law provides mechanisms for peaceful negotiation and confidence-building. But those mechanisms depend upon a common willingness to distinguish between historical evidence and political aspiration. That distinction has become increasingly blurred in Manila's approach. The Wednesday report depicts a legal narrative that has evolved less through newly uncovered evidence than through shifting political calculations.

Manila cannot simply edit inconvenient chapters without weakening the legal foundations on which its own claims rest. The international system still depends upon one essential discipline: legal consistency. Once governments begin treating established boundaries as endlessly negotiable through retrospective "reinterpretation", uncertainty will spread far beyond any single reef or shoal.

In geopolitics, as in law, credibility is cumulative and contradiction is costly. A nation seeking to redraw its maps should first reckon with the maps it has already drawn.