Upon learning of the treaty , Lhasa immediately telegraphed Beijing to declare that the treaty was unacceptable. It is also important to note that Chinese troops were occupying large parts of Tibet at the time this treaty was signed. Since this treaty was signed under duress it was null and void since, according to Article 52 of the Vienna Conventions of the Law of Treaties, any agreement signed under duress is void. Furthermore, China began to violate the terms of the agreement immediately following its signing. There is no legal justification for China's interference with Tibet's territorial integrety.
Forceful annexations are in violation of international law.
Therefore China's invasion and continuing occupation of Tibet did not confer any rights to China, rather, China is guilty of an illegal military invasion colonization of Tibet in violation of international law. The right to self-determination is also set forth in the Universal Declaration of Human Rights, which is widely recognize as customary international law. That definition includes objective components such as a common race, language, religion, territory, and history as well as the subjective component of a common awareness as a people. Tibetans clearly meet both the objective and the subjective components of this definition for what constitutes a people. Tibetans are a distinct ethnic group with their own language, religion, culture and history completely distinct from that of the Chinese people.