The Energy Charter Treaty (ECT) has come under increased criticism in recent years in connection with some investors’ invocation of its dispute resolution provisions to challenge policy initiatives aimed at advancing the transition to greener economies. A number of European states have announced their intent to withdraw, and a vote on a “modernized” version of the ECT has been postponed indefinitely. On July 7, 2023, the European Commission recommended the withdrawal of the EU from the ECT. For EU energy sector investors with investments in EU member states in particular, it remains uncertain whether international arbitration under the ECT will remain a viable avenue to resolve such disputes, and a careful analysis of existing contracts and other potentially applicable investment treaties will be needed to determine the extent of alternative remedies available to such investors. For others, these developments foreshadow growing dispute risks that will continue to arise as states attempt to juggle obligations owed to investors under investment treaties vis-à-vis international environmental law obligations that underlie agreements that states have made to transition to greener economies.