Many states have responded to the current geopolitical uncertainties by seeking to increase their “strategic sovereignty”. In the EU, this reorientation is taking place under the banners of “strategic autonomy” and, more recently, “open strategic autonomy” (OSA), where the EU is increasingly employing new forms of unilateral trade measures. What characterises the general geopolitical context also applies to the international energy landscape, which is today characterized by an unprecedented level of uncertainty. Experts have therefore urged the EU to strive for strategic sovereignty in energy matters as well. As the EU Internal Energy Market is central to this, it needs to be protected by complementary new and partly novel unilateral trade instruments. Three “horizontal instruments” have been considered to be of crucial importance in this context, namely the EU Investment Screening Regulation, the EU Carbon Border Adjustment Mechanism (CBAM) and the EU Foreign Subsidies Regulation. This study seeks to clarify the extent to which these new instruments may violate of the World Trade Organization (WTO) law. This Chapter provides a brief introduction to these issues.