Unconventional Ties? States, Non-State Actors, and Weapons of Mass Destruction.

The threat of deliberate proliferation of chemical, biological, radiological, and nuclear (CBRN) weapons from states to terrorist groups has been a major source of concern for governments and publics worldwide, playing a major role in their threat perceptions, policies, and politics. While the rationale underlying this threat is compelling, it is belied by the paucity of incidents involving CBRN proliferation and use. The puzzle, therefore, is why have we not seen this threat materialize with much greater frequency? To answer this question, this paper reviews the evolution of the deliberate proliferation threat, examines the puzzle using insights from international relations and organizational theories, and finally analyzes it against the empirical record. It identifies very strong reasons that would discourage states, including "rogue states," from providing CBRN technology to terrorist groups. It also proposes that a major predictor of terrorist acquisition and use of CBRN weapons is the extent to which the group is ideal- rather than politically-driven. Using a newly constructed dataset, we find very strong support for our theoretical skepticism concerning deliberate proliferation and for our claims regarding the role of idealism in CBRN attacks. In light of these findings, this paper calls for a more nuanced and sophisticated approach to the issue of terrorist procurement and use of CBRN weapons. ..PAT.-Unpublished Manuscript [ABSTRACT FROM AUTHOR]