`If ever there was a Year of Europe, 1989 clearly was such a year ... It is for the end of the cold war more than any other important development that 1989 will be remembered ... However, political stability in the 1990s wil greatly depend on whether the North manages both to reconstructeconomies in Europe and rescue Third World economies from bankruptcy. It is no small agenda that is ahead of us.' Dr Walther Stutzle, SIPRI Director, in the introduction to the SIPRI Yearbook 1990. The SIPRI Yearbook 1990 continues SIPRI's review of the latest developments in nuclear weapons, nuclear explosions, world military expenditure, the international arms trade, chemical and biological weapons, the military use of outer space, ongoing armed conflicts, and European arms control, andpresents the unique annual calendar of military activities required by the Stockholm Document. Efforts to control the arms race - in nuclear, chemical, biological, conventional, and space weapons - are described, and the status of negotiations and agreements is analysed. The SIPRI Yearbook 1990 includes all the usual features, together with a number of new ones. It examines the relationship between debt, financial flows, and international security, and documents the 1980s as the `lost decade' in terms of welfare and growth in Third World countries. A new SIPRIdata base is introduced on the 100 largest arms-producing companies in the OECD countries and the Third World, and a new data set is presented on purchases of major weapon equipment in the 1980s for all the NATO and EC countries.