The article notes that investments in solar energy have already led to a number of arbitration cases related to the subsequent change in investment incentives. The so-called Solar Cases, initiated by investors under the Energy Charter Treaty (ECT) against Kingdom Spain, Italy and the Czech Republic, focused on the question of whether states could adjust incentives (subsidies and feed-in tariffs) to the detriment of investors after these investors relied on these subsidies to make their investments. Following the results of these arbitration proceedings, the European Union in 2019 decided to revise the text of the ECT. Eight rounds of negotiations were held during 2020 and 2021, the last of which took place in November 2021. Many believe that the reform of the existing treaty has taken too long. In February 2021, France sent a letter to the European Commission on the need for a coordinated EU exit from the ECT. Against this background, Italy’s withdrawal from the ECT on January 1, 2016, as well as Russia’s withdrawal of the signature on the treaty in 2018, are actions that determine the inevitable collapse of the ECT in the very near future. This article is devoted to the study of the causes and legal consequences of these events. Since Russia’s withdrawal from the ECT has already been the subject of study by many Russian and foreign scholars, the author focused their attention on the study of Italian arbitration disputes based on the ECT provisions, as well as on the study of foreign doctrine on this issue. © 2022, Russian Academy of Sciences. All rights reserved.