The Charter and uses of force

Chapter 1 has provided a brief synopsis of the origins of a post-war Charter-based system pertaining to the use of force in international affairs. For the first time, international law fully and formally embraced the Lauterpachtian ground-norm: “there shall be no violence.” Article 2(4) obliges all member states to “refrain … from the threat or use of force”: not just to renounce war but all forms of interstate violence.

This dedication to non-violence by states is coupled in the Charter with an extensive commitment to collective measures against violators of the peace of nations. Article 39 authorizes the Security Council “to determine the existence of any threat to the peace, breach of the peace, or act of aggression,” and empower it to “make recommendations, or decide what measures shall be taken … to maintain or restore international peace and security.” Article 25 requires all members of the United Nations to join in implementing such decisions. Finally, Article 42 authorizes the Council, lesser measures having failed, to “take such action by air, sea, or land forces as may be necessary to maintain or restore international peace and security.” To that end, Article 43 pledges all members “to make available to the Security Council, on its call and in accordance with a special agreement or agreements, armed forces, assistance, and facilities, including rights of passage, necessary for the purpose of maintaining international peace and security.”