At the outset it is important to emphasize that any discussion of a dynamic situation such as chemical weapons proliferation can provide only a snapshot of conditions at the time of writing. The aftermath of the Gulf War in the Middle East could have a profound impact. Moreover, unclassified information on some aspects of the problem is hard to come by and the picture is therefore not necessarily in the sharpest focus. New decisions by national authorities or new information can change some important features. Nevertheless, having a base of information and a guide to understanding and interpreting it can aid in the assessment of future developments; the goal of this volume is to provide such a base.
The spread of chemical weapons to states that had not previously possessed them has been a relatively recent phenomenon. Indeed, during the first two or three decades after World War II there was little change in the number of countries believed to have a chemical weapons capability. One possessor nation, Great Britain, destroyed its weapons under a decision taken in 1956. The United States ceased production of chemical warfare (CW) munitions in 1969. Although it resumed production with binary chemical munitions in December 1987, this program was terminated in 1990. The reported use of CW agents by Egypt in Yemen in the 1960s appeared to be but a blip on an otherwise relatively flat trend line. Those who opposed US involvement in Vietnam made much of US use of herbicides and riot control agents there. These actions, which employed agents widely used for agricultural purposes and for maintaining domestic law and order, did not, however, constitute chemical warfare as it is defined by the United States and a few other Western governments.