This chapter examines the UN Security Council, the General Assembly, and the Secretary-General to demonstrate how they carry out the important task of identifying and responding to threats to international peace and security. The case studies of Syria and Iran in this chapter, illustrate what the different theoretical approaches have to say about which actors and forces determine or explain the behavior of international organizations and the consequences for individuals, groups, and societies. This chapter examines the spread of nuclear technology and weapons, with special emphasis on the Nuclear Nonproliferation Treaty (NPT) and the International Atomic Energy Agency (IAEA). It examines the behavior of the UN Security Council and the IAEA to show how international politics and international law affect political calculations and outcomes. NPT illustrates the nexus between international law and international organizations. In addition to being a multilateral treaty, the NPT is a dispute resolution system that manages conflict over the use of nuclear technology among member states.