To enable the reader to get a sense of what diplomacy is and why it is important, this chapter will use two interrelated case studies. The first case study involves the quest to manage the spread of nuclear weapons. The second half of the twentieth century came to be dominated by conflict between two nuclear-armed superpowers, the United States of America (US) and the Union of Soviet Socialist Republics (USSR) – often called the Soviet Union. In this tense climate, diplomacy ensured that few other nation-states developed nuclear weapons. Hence, the diplomatic success in curbing the proliferation of nuclear weapons is a major one, and one that involved non-state as well as nation-state actors.
