Book excerpt: Nuclear proliferation poses a serious threat to international peace and security. The non-proliferation regime is the body of public international law that aims to counter this threat. It has been a cornerstone of global security for decades. This book analyses its main instruments. The book focuses on the Nuclear Non-proliferation Treaty, international trade controls and the International Atomic Energy Agency. It describes the internal mechanics of these mechanisms, their development, and their strengths and weaknesses. It shows how they together are the basis of a political-legal order that is more than the sum of its parts, offering new insights on the role of international law in an area dominated by security-driven politics.