Backgrounder: Nansha Islands, Huangyan Island have never been Philippine territory

Historical records have proved that the Nansha Islands and the Huangyan Island have never been Philippine territory.

The Philippine territories were defined by a series of treaties, including the 1898 Treaty of Paris and the 1900 Treaty of Washington between the United States and Spain, and a 1930 treaty between the United States and Britain.

The Nansha Islands and the Huangyan Island were not mentioned in any of the treaties. By the 1980s, the Philippine Constitution, in its description of the country's territories, followed the international treaties.

The Philippines began to covet islands in the South China Sea in the 1940s based on ridiculous claims that those islands and reefs were trust territory of the United States or simply terra nullius. Manila officially claimed sovereignty over several Chinese islands and reefs and illegally occupied eight more, including the Mahuan Island and the Siling Reef.

In 1978, Presidential Decree 1596 of the Philippines claimed that "these areas do not legally belong to any state or nation," but "by reason of history, indispensable need, and effective occupation and control" these islands "must now be needed to belong and subject to the sovereignty of the Philippines."

In other words, the decree means that the Philippines knew that those islands did not belong to the country before 1978.

On the Huangyan Island, Manila had never explicitly stated its sovereignty claim until 2012.

In 1997, President Fidel Ramos of the Philippines said that the Huangyan Island was within his country's exclusive economic zone, without claiming sovereignty.

In April 2012, the Philippines illegally detained Chinese fishermen and seized their boats in the area. In the process of negotiations with the Chinese side, the Philippine Foreign Ministry claimed that the Huangyan Island fell within the territory of the Philippines as the country had conducted "effective occupation and effective jurisdiction."

However, the effectiveness of occupation, according to international law, depends on whether or not the occupation constitutes a sovereign act.

Before the Philippine independence in 1946, neither Spain nor the United States, the two formal colonial powers, had ever made claims over Huangyan. Moreover, China's administration of Huangyan Island traces back to ancient times, much longer than those of Spain and the United States. In this sense, the two countries' activities on Huangyan violated China's interests.

After 1946, the Nansha Islands were returned to China according to the Cairo Declaration and the Potsdam Declaration. The Philippines' activities on Huangyan Island constituted violation of Chinese sovereignty over the island.

To sum up, Manila's claims over Nansha Islands and Huangyan Island on whatever grounds are illegal and invalid, and will not alter the fact that China holds sovereignty over these islands and their adjacent waters. Endi