Manila's land-grabbing ambition root of disputes

A country's territory is defined by historical facts and international law, which is the cornerstone of modern international relations. In the South China Sea, the territorial boundaries of the Philippines have been established through treaties with binding international legal effect.

However, since the 1970s, the Philippines has repeatedly laid claims to China's Huangyan Island and parts of the Nansha Islands under flimsy pretexts, revealing a sustained ambition to expand its territory.

Such actions not only contradict the legal stance the Philippines upheld for decades post-independence but also threaten the carefully constructed postwar international order and fragile stability in the South China Sea.

Before Spanish colonizers set foot on what is now the Philippines, the region did not have a unified statehood territory or defined boundaries recognized by modern international law.

During the colonial period, the Philippine territorial boundaries were gradually etched and explicitly defined by three international treaties, which were recognized and adopted by the country after it gained independence.

The Treaty of Paris, signed in 1898 after the Spanish-American War, meticulously delineated the boundaries of the Philippine archipelago ceded to the United States. The ceded central and northern territories were confined between 118 and 127 degrees east longitude, whereas Huangyan Island and the Nansha Islands lie west of 118 degrees east longitude.

Two years later, Washington and Madrid signed another treaty ceding several outlying islands, including Sibutu and Cagayan Sulu which were outside the 1898 boundaries to the US.

In 1930, Washington and London signed a convention clarifying the boundary between the State of North Borneo and the Philippine archipelago, further defining the ownership of islands on the Philippine archipelago's southwestern side.

These three international treaties formally defined the territorial limits of the Philippines, which successive governments in Manila recognized for decades since independence. Neither Huangyan Island nor any part of the Nansha Islands was included within these defined limits.

Since the 1970s, however, the Philippines has systematically tried to extend its territorial claims beyond the established limits. In 1971, then president Ferdinand Marcos, father of the current president, formally asserted claims over several islands, shoals and reefs in the Nansha Islands and subsequently deployed troops to occupy eight features, including Mahuan Island, Feixin Island and Zhongye Island.

The claim over Huangyan Island emerged in 1997, when Manila disrupted a Beijing-approved amateur radio expedition to the island. Beijing lodged a protest, but Manila persisted and began asserting territorial sovereignty over Huangyan Island.

As a recently released report titled "Historical and Legal Critique of the Philippines' Territorial Claims in the South China Sea" indicates, over the past three decades, the Philippines has put forward a series of untenable and self-contradictory arguments such as "geographic proximity", "early occupation", and "treaty reinterpretation" to support its claims over the features. None of these claims can withstand historical and legal scrutiny.

Manila's position is further weakened by its contradictory stance. Until the 1990s, official Philippine maps placed Huangyan Island outside its territorial boundaries.

In 1990, the Philippine ambassador to Germany, Bienvenido A. Tan Jr, stated in a letter that Huangyan Island is not within the Philippines' territorial sovereignty. In 1994, the country's National Mapping and Resource Information Authority issued an official certification confirming that the country's territory, as defined by Article 3 of the Treaty of Paris, does not include Huangyan Island.

According to the principles of recognition and estoppel in international law, a state's official statements and actions constitute valid affirmation of legal facts. Thus, Manila's current claims breach its own official statements.

The Philippines' relentless attempts at unlawful territorial expansion pose a grave threat to the international rule of law, regional stability, and the postwar global order. The United Nations Charter stipulates that member states shall refrain from the threat or use of force against the territorial integrity of any state.

Manila seized Chinese islands and reefs in the Nansha Islands by force, and has sought to legitimize its illegal occupation through domestic legislation, maritime operations, and media manipulation. These actions blatantly challenge the international legal system anchored by the UN Charter.

In recent years, the Philippines has frequently dispatched naval vessels and coast guard ships into the waters adjacent to Huangyan Island and the Nansha Islands, escalating provocations with dangerous maneuvers such as ramming and close-in surveillance.

These actions violate the core commitments of the Declaration on the Conduct of Parties in the South China Sea, hinder consultations on the Code of Conduct in the region, and disrupt the cooperative momentum between China and the Association of Southeast Asian Nations.

After World War II, international instruments such as the Cairo Declaration and the Potsdam Proclamation clearly stated that lands seized by Japanese aggressors were to be returned to their rightful owners.

Accordingly, China resumed exercising its sovereignty over the South China Sea islands. The Philippines, which gained independence only after the war, had acknowledged that these islands were not in its territory. However, driven by political interests, it reversed its stance and challenged the territorial order established by the international community.

The ancient Chinese wisdom of respecting one's boundaries resonates with modern international law on territorial sovereignty.

Expanding territorial boundaries infringes on others' rights and undermines the international order. Manila must recognize that its quest for unlawful territorial expansion will not succeed.

The author is an assistant professor at the China Institute for Marine Affairs.

The views don't necessarily reflect those of China Daily.