United Nations sanctions and countermeasures in State responsibility are the two major enforcement mechanisms of international law. The Security Council imposes measures provided for in Article 41 of the UN Charter for the sole purpose of the maintenance of international peace and security, while States are entitled to recourse to countermeasures to ensure the discontinuance of the wrongful act infringed on themselves, and, if relevant, seek reparations against the damage caused by such an act. This work endeavored to make a comparative analysis of both mechanisms in order to determine differences between coercive acts of the UN sanctions mechanism and that of countermeasures, as well as similarities both regimes may share. On the basis of the UN sanctions practice and countermeasures taken in conjunction with the cases of the Ukrainian crisis, the downing of the Russian jet by Turkey and the Qatar-Gulf crisis, this study argues that a sharp distinction between UN sanctions regime and the legal regime of countermeasures in State responsibility has to be made although the similarities of acts imposed by these two regimes may blur this distinction.