The proliferation of nuclear, biological, and chemical weapons (NBC) remains a profound problem for the international community for a number of reasons. Efforts to newly acquire such weapons typically indicate that an interstate dispute has fallen into a downward spiral of obduracy and mutual estrangement, breeding intensified fears of malign intentions, and undermining the possibility for the cooperative pursuit of regional interests and the peaceful use of advanced nuclear, biological, and chemical technologies. Terrorist acquisition of such weapons is constrained, but not inconceivable. NBC terrorism is an acute threat, because terrorists are more likely to use weapons as soon as possible after acquiring them, rather than maintaining them for deterrence. Differences in perceptions of the threat of NBC proliferation and in the adequacy of the UN to deal with such threats have forced the organization to search for a redefinition of its role.
Regimes for the nonproliferation of NBC face a crisis in two dimensions. The first dimension involves a series of startling revelations about the extent and linkages of weapons programs around the world. These revelations have occurred against a backdrop of both positive and negative trends in relation to state-based programs. But increases in the availability of requisite technology and the likelihood of massive terrorist attacks have produced a heightened perception of NBC threats. The question remains whether this heightened perception will be translated into a strengthened nonproliferation framework.
The second dimension of the crisis concerns the ability of the international community to devise effective responses. This dimension is defined by the rigid bipolar debate over unilateral versus multilateral responses. Ad hoc and coalition efforts have been initiated outside the multilateral framework, particularly by the US, in response to the seeming inadequacies of multilateralism. Critics of such initiatives claim that they bypass and erode the multilateral framework, which is essential for the long-term reduction of NBC threats. The key challenge for the international community is to reconcile the different roles of unilateral, bilateral, plurilateral (i.e., multinational, but not within the multilateral framework), and multilateral instruments to provide for a comprehensive response.