Abstract
Provisional application of treaties is governed by international law of treaties, codified in the Vienna Convention of 1969. However, its Article 25 is very brief which may contribute to problems of interpretation and application in practice.
The UN International Law Commission thus revisited the topic after more than 50 years. Currently, it is completing draft guidelines which clarify rules on the provisional application of treaties, concerning also treaties concluded by international organizations.
While based on an agreement between the States or international organizations concerned, the provisional application can also be in practice influenced or limited by rules of internal law. This is in particular the case where the treaty includes so-called (non)consistency clause referring to internal laws.
The fluctuations of interpretation of such clauses can be best seen in the Yukos case.