The SIPRI Yearbook is as an authoritative and independent source of data and analysis on armaments, disarmament and international security. It provides an overview of developments in international security, weapons and technology, military expenditure, arms production and the arms trade, and armed conflicts and conflict management, along with efforts to control conventional, nuclear, chemical and biological weapons. This 50th edition of the SIPRI Yearbook covers developments during 2018, including - Armed conflicts and conflict management, with an overview of armed conflicts and peace processes as well as a focus on global and regional trends in peace operations - Military expenditure, international arms transfers and developments in arms production, - World nuclear forces, with an overview of each of the nine nuclear-armed states and their nuclear modernization programmes - Nuclear arms control, featuring North Korean-US nuclear diplomacy, developments in the INF Treaty and Russian-US nuclear arms control and disarmament, and implementation of Iran's nuclear deal - Chemical and biological security threats, including the investigation of allegations of chemical weapon use in the Middle East and the attempted assassination in the United Kingdom - Conventional arms control, with a focus on global instruments, including efforts to regulate lethal autonomous weapon systems and explosive weapons in populated areas, and dialogue on international cyber security - Dual-use and arms trade controls, including developments in the Arms Trade Treaty, multilateral arms embargoes and export control regimes, including the challenges of seeking to control transfers of technology as well as annexes listing arms control and disarmament agreements, international security cooperation bodies, and key events in 2018.