How to Put an End to intra-EU Investment Arbitration under the Energy Charter Treaty (Fast): Amendment, Withdrawal, Modification?

The energy charter treaty (ect) has given rise to major political and legal controversies for years, culminating in the recent treaty exit of the european union (eu) and some of its member states, while other member states remain parties to the modernized ect. This reliance on different problem-solving strategies – amendment, withdrawal, and interpretation or modification – showcases serious coordination problems and legal difficulties that can arise when the eu and its member states act together at the international level in the context of mixed agreements. The article shows that the parallel pursuit of these strategies results in a complex and fragmented web of legal relations among different eu member states falling short of the goal to exclude all future intra-eu investment arbitration under the ect. The identified legal limitations of the different strategies would – by and large – also apply in extraeu relations, for instance in case of inter se agreements with third countries aiming to exclude investment arbitration under the ect.