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conquest; territorial change; aggression

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International Law | Law


The prohibition on territorial conquest is a cornerstone of the international legal order. The United Nations Charter bans the use of force as a tool of international relations, even when used to rectify prior injustices. Thus territory taken by force has the status of ill-gotten gains, and cannot be kept by the victor. An important corollary is that third-party states cannot recognize the sovereignty of the conqueror or otherwise treat the acquisition as lawful.

Despite the Charter, nations sometimes acquire or try to acquire territory through force. This paper, part of the proceedings of the American Society of International Law's 102nd annual meeting, discusses the preliminary results of an ongoing research effort to systematically explore the international response to every consummated conquest since the entry into force of the UN Charter. The question is, given a conquest, what is the expected international reaction?

This project classifies international reactions as condemnatory, accepting, or silent/acquiescing. There are close to 20 conquests depending how one counts (deciding what counts as a conquest is perhaps the major methodological issue of this project).

The preliminary results are that systematic international condemnation – a resolution of the U.N. Security Council or General Assembly – occurs in under 1/3 of the cases. On the other hand, some conquests have won overwhelming international acceptance; these surprisingly include both conquests of entire nations (Tibet and South Vietnam.)

While territorial conquest has been relatively infrequent in the post-World War II period, most conquests have not been condemned by the international community. Indeed, open acceptance is as common as condemnation. The small likelihood of international opposition to conquest suggests that the relatively low incidence of conquest should be attributed to causes other than the non-recognition norm. This does not mean that the anti-conquest norm has no force or "compliance pull," but it does suggest that condemnation and nonrecognition are not likely to play a significant role in decisions about whether to conquer.