This short Chapter recalls that energy has been at the heart of European integration from the very beginning, as the EU integration process was started with the creation of the European Coal and Steel Community (ECSC) and the European Atomic Energy Community (Euratom). This Chapter in particular refers to a previous study which, on the one hand, emphasized that today the EU’s Internal Energy Market is central to the pursuit of the EU’s goal of strategic energy autonomy and, on the other hand, underlined that the EU’s Investment Screening Regulation, the EU’s CBAM mechanism, and the EU’s Foreign Subsidies Regulation are crucial to the protection of the EU’s Internal Energy Market. This Chapter thus in particular serves as a brief introduction to the following core chapter of this study, which will examine the extent to which these instruments are compatible with WTO law.