In 1958, shortly after China issued a statement on its territorial waters, including the Nansha and Xisha islands, Pham Van Dong, then premier of DRV, said Vietnam respected China's sovereignty statement on its territorial waters. Thus Vietnam has long recognized China's sovereignty over the islands in the South China Sea.

Some Vietnamese maps published in the 1960s and the 1970s even mark the Nansha Islands as part of Chinese territory. Moreover, a Vietnamese geography textbook published in 1974 depicted the islands in the South China Sea, including Nansha and Xisha islands, as an arch and compared it to a "great wall" at sea safeguarding the Chinese mainland.

As for the Philippines, its interest in the Nansha Islands began shortly after it gained independence in 1946. But it did not clear its stance until 1971 when studies showed the waters could be a storehouse of oil. In 1978, then president Ferdinand Marcos issued an ordinance claiming sovereignty over the Nansha Islands (spread over an area of about 64,976 square nautical miles), and named them the Kalayann Island Group.

The Philippines bases its claim over the islands on three premises. First, it says the islands are the lifeline of its national security and economy. Second, the Philippines is geographically closest to the islands. And third, it claims that before the Philippines laid claim, the islands did not belong to any country. But the reasons cannot justify the Philippines' sovereignty over the islands.

No country can claim sovereignty over any land or water body which belongs to another country by citing economic and security concerns. No matter how desperate the Philippines is to control the resource-rich waters, it cannot jeopardize China's interests by claiming the islands.

Also, geographical closeness does not necessarily mean the islands belong to the Philippines. Take the Christmas Island for example. Although it is hundreds of nautical miles away from the Australian mainland and less than 200 nautical miles from the Indonesian island of Java, it is still part of Australian territory. So the Philippines cannot claim the Nansha Islands based on geographical closeness.

More importantly, the Nansha Islands were not res nullius before the Philippines' claims. China's sovereignty over the islands was established long ago. And although China's sovereignty over the islands weakened in modern times, it reaffirmed it after the end of World War II, enduring to defend them against intrusions by Vietnam, the Philippines and other countries.

On more than one occasion, Vietnam has acknowledged China's sovereignty over the islands in the South China Sea, and the Philippines cannot justify its claim. Hence, both countries should acknowledge China's sovereignty and stop distorting history.

The author is a professor at the Center for Southeast Asia Studies, Xiamen University, Fujian province.

(China Daily 06/15/2011 page9)