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 responsibility and has probably brought about more violence, rather 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", allowing a right for humanitarian intervention. It has been argued that this could create a flexible application of concepts 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. The International Court of Justice advisory opinion on Kosovo's declaration of independence claims that territorial integrity is not violated as far as international law is concerned by declarations of independence in themselves.