On a provision in international law

January 19, 2024 marked the 50th anniversary of the Chinese government's illegal use of force to occupy Vietnam's Hoang Sa archipelago. On social networking sites, a viewpoint was shared:“According to international law, if there is a territorial dispute and there is a gap of 50 years or more between protests, the territorial claims become invalid. Vietnam's Hoang Sa has been occupied by China for 50 years, but Vietnam has not submitted any protests or lawsuits to the International Court of Justice or the International Tribunal for the Law of the Sea. If there are no protests or lawsuits, according to international law of the sea, Vietnam is considered to have accepted the permanent loss of Hoang Sa and some islands in Truong Sa to China...”.

Is this true?

International law reinforces the principle of sovereign equality among all states.

Public international law, also known as International Law, is a set of norms, rules and practices that regulate the relations and interactions between subjects participating in international relations. This is a combination of countries in different fields such as armed conflicts, human rights, seas, islands, space, trade, territorial borders and diplomatic relations. Public international law standards create a common framework within which subjects of International Law operate and contribute to the existence of generally stable, organized and consistent international relations.

Public international law also provides normative guidance as well as common methods, mechanisms and conceptual language for international actors, i.e. primarily sovereign states, but also other international organizations.

Treaties are one of the main sources of public international law, if states do not have equal influence in international organizations based on treaties, this means that the will of a powerful state will prevail over a smaller, weaker state. Therefore, legal equality will be meaningless if it cannot be translated into real equality, at least at the level of law-making in international organizations.

In particular, the United Nations Charter sets out the fundamental principles of modern international law, notably:“Strictly restrict the right to use force against other nations”and“It is strictly forbidden to seize territory by force.”

Thus, international law is designed to reinforce the principle of sovereign equality among all states. Therefore, it will also limit certain actions of subjects of international law, such as preventing states from engaging in a course of conduct that is inconsistent with international obligations.

Modern international law has criticized and rejected the principle of acquiring sovereignty by prescription, because it has been repeatedly used to justify acts of aggression. The use of force to occupy another country's territory never brings legitimate sovereignty to the country that uses force.

Therefore, the Chinese government's occupation of the Hoang Sa archipelago and some islands in the Truong Sa archipelago by force, no matter how long this occupation lasts, is still illegal.

Using force to invade is an act that goes against international law.

Territorial acquisition is the establishment of a state's geographical boundaries of sovereignty over a new territory in a manner consistent with the principles of international law. The establishment of state sovereignty over territory must comply with certain principles of international law. Therefore, territorial acquisition must also comply with the basic principles of international law. One of the basic principles is "Prohibition of the use of force or threat of use of force”.

This principle itself was formed in the struggle against fascism and was affirmed in the Charter of the United Nations. At first, this principle expressed the desire of peoples to establish a just international order after the war. Resolution No. 26/25 (1970) of the United Nations General Assembly on the fundamental principles of international law clearly stated: “The territory of a State shall not be the object of acquisition by another State resulting from the threat or use of force. No acquisition resulting from the threat or use of force shall be recognized as legal”.

As for the Chinese government, although they claim sovereignty over the Paracel and Spratly Islands (China's name for the Hoang Sa and Truong Sa archipelagos of Vietnam), they do not have any contemporary original written documents to prove it. And more specifically, the records of famous Chinese people all affirm that the Hoang Sa and Truong Sa archipelagos belong to Vietnam's sovereignty as stated in theOverseas MemoirsMaps by Venerable Shi Lian Shi Da Shan or maps from the early Qing Dynasty to the end of the Republic of China all draw the southernmost point of China only to Qiongzhou Island (Hainan Island).

Therefore, China's use of force to invade the Hoang Sa archipelago and some islands in the Truong Sa archipelago of Vietnam is a violation of modern international law in Article 2, Clause 4 of the United Nations Charter. Accordingly, the use of force to occupy another country's territory never brings legal sovereignty to the country using force. And so, it is clear that the act of using force to occupy has no value for international recognition.

Regarding the legal basis and sovereignty of Vietnam over the two archipelagos of Hoang Sa and Truong Sa, through the historical scientific bases presented above, it has been affirmed that the sovereignty throughout history over the two archipelagos of Hoang Sa and Truong Sa belongs to Vietnam. Professor Monique Chemiller Gendreau - Faculty of Public Law and Political Science at the University of Paris VII has affirmed that:“Vietnam's rights are inherent and certain, even in the case that China's ambitions and claims have been materialized through occupation based on force... The arguments that China has put forward so far do not allow the confirmation of the existence of ancient legal connections between the Chinese court and these territories, so that today people can understand them as connections like sovereignty”^[*].

Vietnam's sovereignty over the Hoang Sa and Truong Sa archipelagos of Vietnam has been affirmed early and continuously throughout historical periods, although due to the continuous war, many ancient Vietnamese documents have been lost or misplaced. However, the remaining documents to date and official history are still very rich, objective, scientific, and consistent enough to prove Vietnam's sovereignty over the Hoang Sa and Truong Sa archipelagos. Meanwhile, on the Chinese side, although they claim sovereignty over the Xisha and Nansha (China's name for the Hoang Sa and Truong Sa archipelagos of Vietnam), they have not been able to present any contemporary original written documents to prove that.

And more specifically, the records of Chinese celebrities all affirmed that the two archipelagos of Hoang Sa and Truong Sa belong to Vietnam's sovereignty. It is from the above-mentioned works that have created a "background" of written documents with historical and legal scientific bases for the Socialist Republic of Vietnam to once again affirm Vietnam's sovereignty over the two archipelagos of Hoang Sa and Truong Sa. Through the system of historical scientific bases, our State has affirmed that the two archipelagos of Hoang Sa and Truong Sa belong to Vietnam's sovereignty in the past, present and future.

Therefore, it can be firmly affirmed that China's use of force to occupy the Hoang Sa archipelago in 1974 and the Truong Sa archipelago in 1988 violated three principles recognized by modern international law at the same time:the principle of prohibition of the threat or use of force, the principle of inviolability and territorial integrity of the stateandprinciple of national self-determination. Those actions are clearly condemned by international law and progressive public opinion around the world. Therefore, those illegal actions can never be a legitimate basis for the Chinese government's sovereignty claim.

In addition, through the historical system of Vietnam, China and Western countries, it is clearly shown that the feudal state of Vietnam established sovereignty over the two archipelagos of Hoang Sa and Truong Sa very early and continuously. Therefore, in the case of the Hoang Sa and Truong Sa archipelagos of Vietnam currently occupied in whole or in part by neighboring countries such as China, Taiwan, the Philippines, Malaysia and Brunei, it is the method of possession according to prescription. That is, this method of acquisition is formed from the effective possession of territories that are not terra nullius, or territories that were acquired illegally, or territories whose circumstances at the time of acquisition did not clearly determine the legality of the acquisition. Therefore, the fact that the Socialist Republic of Vietnam always affirms its sovereignty over the Hoang Sa and Truong Sa archipelagos as well as continuously protests with the same content over and over again has created a legal consequence that these countries cannot legally acquire the Hoang Sa and Truong Sa archipelagos of Vietnam.

[*]Vietnam Military History Institute (2016), The process of exploring, establishing, implementing and protecting Vietnam's sovereignty over the Hoang Sa and Truong Sa archipelagos (Selected from Military History Magazine), People's Army Publishing House, Hanoi, p. 404.