Territorial integrity is the principle under international law where sovereign states have a right to defend their borders and all territory in them from another state. It is enshrined in Article 2(4) of the UN Charter and has been recognized as customary international law.[1] Under this principle, forcible imposition of a border change is an act of aggression.
In the post-World War 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."[2]
Some of the strongest safeguards of territorial integrity are rule of law such as Charter of the United Nations and nuclear deterrence.[3]
Scholars have debated the existence of a territorial integrity norm since the end of World War II.[4][5] Conquest of large swaths of territory has been rare,[6] but states have since 1945 continued to pursue (and often successfully) the violent annexation of small swaths of territory.[5][7]