The United Nations Security Council has primary responsibility for maintaining international peace and security. In discharging its powers it must act in accordance with the Purposes and Principles of the UN, and observe the rules governing voting and procedure established in the Organisation’s Charter. The Council adopts mandatory resolutions that may establish obligations for members and non-members, and such obligations trump conflicting obligations originating from any other international agreement. Member States must cooperate with the Organisation and among themselves, in the implementation of any action prescribed by the Council against States whose behaviour the Council considers an act of aggression, or a threat to, or breach of, international peace and security. This book analyses resistance to Security Council resolutions and puts forward a theory of lawful resistance. Sufyan Droubi takes a positivist approach to the UN Charter regarding it as a constitution. Special emphasis is placed on the construction of the Charter’s meaning through the practice of both organs and Members of the UN and on the need to enhance the effectiveness of the Organization with due respect to the rule of law. The book proposes that nonviolent resistance to a mandatory resolution of the Security Council, on grounds that the latter is incompatible with the Charter or jus cogens norms, may be considered lawful under the Charter if some elements are present. In exploring a number of case studies of individual and collective State resistance to mandatory Council resolutions, the book proposes that resistance may function as a rudimentary instrument of accountability and protection of the Charter and jus cogens, in the absence of more mature mechanisms of judicial review. The book will be of excellent use and interest to scholars and students of constitutional international law and international relations.