The SIPRI Yearbook is 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 52nd edition of the SIPRI Yearbook covers developments during 2020, includingBL Armed conflicts and conflict management, with an overview of armed conflicts and peace processes across the Americas, Asia and Oceania, Europe, the Middle East and North Africa, and sub-Saharan Africa, as well as a focus on global and regional trends in peace operations and the United Nations appeal for a global ceasefire to address the Covid-19 pandemicBL Military expenditure, international arms transfers and developments in arms productionBL World nuclear forces, with an overview of each of the nine nuclear-armed states and their nuclear modernization programmesBL Nuclear arms control, featuring developments in Russian–United States strategic dialogue, Iran's nuclear deal and the multilateral nuclear arms control and disarmament treaties, including the entry into force of the Treaty on the Prohibition of Nuclear WeaponsBL Chemical and biological security threats, including the impact of the unfolding Covid-19 pandemic, the investigation of allegations of chemical weapon use in Syria and developments in the international legal instruments against chemical and biological warfareBL Conventional arms control, with a focus on global instruments, including efforts to regulate lethal autonomous weapon systems, state behaviour in cyberspace and space, and developments in the Open Skies TreatyBL Dual-use and arms trade controls, including developments in the Arms Trade Treaty, multilateral arms embargoes and export control regimes, and review processes in the legal framework of the European Union for such controlsas well as annexes listing arms control and disarmament agreements, international security cooperation bodies, and key events in 2020.