Effective Application of the Rule on Fundamental Change of Circumstances to Treaties Contravening the 1997 Polish Constitution

A fundamental change of circumstances is one of the more controversial reasons for the termination of a treaty. The fact that it was included in the 1969 Vienna Convention on the Law of Treaties gave rise to many disputes among legal scholars, including whether the solutions adopted then embodied customary law. In this context, an interesting case is offered by Poland which in 1999 invoked specific provisions of the Convention, both substantive and procedural, including a fundamental change of circumstances, and considered several treaties from the period of Soviet domination terminated with retroactive effect from 1997. The article discusses actions by the states involved and their legal effects. Interestingly, this is one of very few examples where a fundamental change of circumstances was an effective reason for bringing about the termination of treaties in a manner that has not drawn any objections nor has brought about any international accountability.