In recent years there has been tension between this principle and the concept of humanitarian intervention under Article 73.b of the United Nations Charter "to develop self-government, to take due account of the political aspirations of the peoples, and to assist them in the progressive development of their free political institutions, according to the particular circumstances of each territory and its peoples and their varying stages of advancement Territorial integrity and humanitarian intervention collided in the Kosovo War.
The League of Nations was intended to uphold territorial integrity and other principles of international law. It did condemn the Italian invasion of Ethiopia. It broadly supported the Chinese Republic over the creation of Manchukuo in Manchuria and eastern Inner Mongolia. Most historians say that the League was discredited by its failure to make these judgements effective.
With the formation of the United Nations (UN) and, later, such organizations as the Conference on Security and Cooperation in Europe (now OSCE), territorial integrity became a part of international resolutions. The Helsinki Final Act dealt with both inviolability of frontiers and territorial integrity of States, among other things.
Prince Hans-Adam II of Liechtenstein, speaking to the International Institute for Strategic Studies on 25 January 2001, argued for a more flexible approach to territorial integrity, in line with historical norms, saying: Let us accept the fact that states have lifecycles similar to those of human beings who created them. Hardly any Member State of the United Nations has existed within its present borders for longer than five generations. The attempt to freeze human evolution has in the past been a futile undertaking and has probably brought about more violence than if such a process had been controlled peacefully. Restrictions on self-determination threaten not only democracy itself but the state which seeks its legitimation in democracy.
At the 2005 World Summit, the world's nations agreed on a "Responsibility to Protect" giving a right of humanitarian intervention. It has been argued that this could create a flexible application of concept of sovereignty and territorial integrity, easing the strict adherence and taking into account the de facto status of the territory and other factors present on a case by case basis. The United Nations Security Council Resolution 1674, adopted by the United Nations Security Council on April 28, 2006, "Reaffirm[ed] the provisions of paragraphs 138 and 139 of the 2005 World Summit Outcome Document regarding the responsibility to protect populations from genocide, war crimes, ethnic cleansing and crimes against humanity
However, this responsibility to protect refers only to the ability of external powers to override sovereignty and does not explicitly involve the changing of borders.