The process of imposing and implementing unilateral sanctions outside the framework of the United Nations has increased in recent decades. At the same time, there remains disagreement among states regarding the principle and scope of the legal legitimacy of unilateral sanctions. This raises the question whether, if a state considers such sanctions to be unlawful, international law possesses sufficient capacity to confront unilateral sanctions and what challenges, from the perspective of international law, stand before target states in their efforts to respond. This question may be addressed at two levels: the level of legal foundations and the level of international institutions. At the level of legal foundations, various principles and rules may be invoked to challenge unilateral sanctions. At the institutional level, political, economic, and legal international institutions possess capacities that may be utilized in efforts to counter unilateral sanctions. In addition, many countries have enacted domestic legislation to protect their companies and commercial actors against extraterritorial sanctions. Nevertheless, it appears that due to certain deficiencies within international law, as well as the lack of alignment between the capacities of international law and the realities of the international economy, legal measures adopted to counter unilateral sanctions have thus far not achieved sufficient success.