This annual report continues and updates SIPRI's charting of the latest developments in nuclear weapons, nuclear explosions, world military expenditure, the international arms trade, chemical and biological weapons, conventional weapon technology, the military use of outer space, and current armed conflicts of the world. The Yearbook also describes efforts to control the arms race, and analyzes the status of negotiations and agreements. A special section reviews the INF treaty signed in December 1987 by the United States and the Soviet Union, the ABM Treaty, the Iran-Iraq war, and disarmament and development.