Threat of force (public international law)

Threat of force in public international law is a situation between states described by British lawyer Ian Brownlie as:

The 1969 Vienna Convention on the Law of Treaties notes in its preamble that both the threat and the use of force are prohibited. Moreover, in Article 52, it establishes the principle that if threats of using force are made during diplomatic negotiations, then any resulting treaty is invalid, stating "A treaty is void if its conclusion has been procured by the threat or use of force in violation of the principles of international law embodied in the Charter of the United Nations".

...
Wikipedia