The Chinese government unilaterally issued a territorial waters claim on September 4, 1958, when the UN’s 1^st Conference on the Law of the Sea failed to reach an agreement on the extent of each nation’s territorial waters. In that situation, each country issued its own territorial waters claim. For instance, the US claimed territorial waters of 3 nautical miles, some other countries 4.5 nautical miles, and China 12 nautical miles.

Prime Minister of the Democratic Republic of Vietnam Pham Van Dong sent a diplomatic note to Chinese Premier Zhou En Lai on September 14, 1958 which said: “The government of the Democratic Republic of Vietnam acknowledges and supports the Declaration dated September 4, 1958, by the Government of the People’s Republic of China regarding its decision on the extent of China’s territorial sea.”

Wrong deduction

China says its 1958 territorial sea declaration claimed that the 12-nautical-mile territorial sea applied to all of China’s islands including Xisha and Nansha (China’s names for Vietnam’s Hoang Sa and Truong Sa archipelagos) and that Vietnam’s 1958 diplomatic note “acknowledged and supported” China’s territorial waters declaration, which means Vietnam acknowledged and supported China’s territorial policy, since that policy was based on its territorial sovereignty.

Doctor Thang says the declaration was a territorial waters sea declaration, not a territorial sovereignty declaration. Prime Minister Pham Van Dong’s diplomatic note acknowledged and supported China’s claim of 12-nautical-mile territorial waters. An acknowledgement of the extent of territorial waters does not equate to an acknowledgement of territorial sovereignty. Sovereignty and territorial waters are two different matters. China’s claim of territorial waters surrounding its islands doesn’t mean China has sovereignty over all the islands in those waters. China’s claim of territorial waters contiguous to the Hoang Sa and Truong Sa archipelagos (part of Vietnam’s territory) does not mean China has sovereignty over these archipelagos.

Under international law, the declaration is only valid for China and clearly not valid or binding on other countries. A unilateral declaration, by China claiming all islands disputed with other countries cannot give China sovereignty over those islands.

Land determines maritime rights and territorial waters surround a mainland or islands but a unilateral declaration of territorial waters doesn’t give a nation any territorial sovereignty rights. So China’s claim of territorial waters bordering the Hoang Sa and Truong Sa archipelagos did not give China any sovereignty status and its sovereignty claims are invalid. The two archipelagos have always belonged to Vietnam.

The 1958 diplomatic note does not relinquish Vietnam’s sovereignty over Hoang Sa and Truong Sa

Legally Vietnam was temporarily divided into two parts along the 17th parallel by the Geneva Accords signed on July 21, 1954. In the final statement of the Geneva conference, all parties committed to respect the independence, sovereignty, national unity, and territorial integrity of Vietnam. The government of the Republic of Vietnam temporarily managed the territory south of the 17th parallel, and the government of the Democratic Republic of Vietnam managed the north of the 17th parallel. The Republic of Vietnam continued to exercise the time-honored sovereignty of Vietnamese people over Hoang Sa and Truong Sa archipelagos in administrative and marine activities.

The naval force of the Republic of Vietnam fought a Chinese invasion of Hoang Sa in 1974 to defend territorial sovereignty. China occupied Vietnam’s Hoang Sa islands by force in 1974, seriously violating international law, but the Chinese presence in the Hoang Sa archipelago has not given it sovereignty status.

After the Geneva Accords in 1954, the government of the Democratic Republic of Vietnam only managed the territory north of the 17^th parallel, so it did not have authority over the Hoang Sa archipelago, which is located south of the 17^th parallel. The 1958 diplomatic note was valid for its content and connected with issues under the authority of the Democratic Republic of Vietnam. Prime Minister Pham Van Dong’s diplomatic note reflected the political views and relations of the Democratic Republic of Vietnam and China. It acknowledged and supported China’s territorial waters claim of 12 nautical miles but in no way relinquished sovereignty over the Hoang Sa and Truong Sa archipelagos.