What qualms may they have?
What are the most significant technical constraints, political constraints, and psychological inhibitory constraints against CBRN use by terrorist networks? How might these be enhanced?
So, what's stopping the terrorists? Holding them back from doing the unthinkable, the devastating, the inevitable? The biggest factor is the damage caused. CBRN weapons inflict mass casualties upon a large area, and the psychological damage is even more widespread. CBRN give a huge payoff with minimal action. "WMD in particular are weapons of choice for causing indiscriminate mass casualties, because they have the potential to inflict casualties far in excess of what is achievable with conventional weapons" (Gurr and Cole 94-5).
Technically, the procurement, maintenance, preparation, and delivery of CBRN weapons is really complicated. Though there are some biological weapons that are relatively easy to create, the weaponization process is prohibitively complex. Gurr and Cole cite that anthrax, a relatively easy biological weapon to make, is incredibly difficult to weaponize. "The most efficient aerosolization systems for BW require considerable technological sophistication, and remain beyond the reach of most states and terrorist groups" (64). The same holds true for chemical and nuclear weapons. Libya reportedly offered one billion dollars for a working nuclear weapon, despite their own clandestine nuclear enrichment program for the same goal (Sublette 2002). Obviously their own enrichment facility was not working out as advertised when procured from the AQ Khan network ("A.Q. Khan" 2004). Though a suitcase or van-sized atomic weapon is not unthinkable to procure, it would be very difficult to maintain until delivery.
Politically, the detonation of a CBRN weapon would completely backfire. First of all, the threat of collateral damage would turn the populace against the cause for which the terrorists fight. Doing so, however, would destroy the popular support on which so many terrorist causes rely.
Killing innocent civilians was seen by some left-wing groups as
tarnishing their image as a revolutionary vanguard in the
pursuit of social justice. In their perception, violence should be
used to gain publicity for their cause and educate the public.
Therefore left-wing violence has tended to be highly discriminate
and limited and indiscriminate acts of violence have not been one
of their core strategies (Ibid. 115).
The government would potentially crack down on the use of CBRN within the target nation, especially if the terror attack was perpetrated by an indigenous revolutionary or ethnic cause. "Some terrorist groups operate within a fairly permissive environment, which would be threatened if they carried out an attack of such magnitude" (Ibid. 122).
Also, the terrorists could kill their own operatives in a CBRN detonation: "Since the use of NBC weapons against population targets in the open air is indiscriminate in nature it will kill any of the terrorists' own people who happen to be in the immediate vicinity of the weapon" (Ibid. 95). The danger posed to their own troops prevents their use.
Psychologically, the inhibitions may run strong with the group; it is the radical fringes of the terror groups about which we must worry. "Within secular terrorist groups there will also generally exist individuals or factions who are prepared to commit the most extreme acts within their capacity. In many cases these elements are kept under control by a less extreme leadership, but occasionally they can gain control of the group, or break away to pursue their own campaign of violence" (Ibid. 153).
The only exception may be in religious groups, who have already overcome the psychological hurdles required to become a member of an apocalyptic cult. "Mass suicides such as the 1978 'Jonestown Massacre' of the members of the People's Temple in Guyana" or the San Diego-based Heaven's Gate cult of Marshall Applewhite are examples of groups of people who are dangerous to themselves and others due to their religious beliefs. "Cults are inherently volatile entities which by their very nature are violent" (Ibid. 135). Having placed themselves "above conventional morality" (Ibid. 142), it is hard to believe they would be unwilling to detonate a nuclear weapon in order to bring about either Armageddon or mass salvation.
Sources:
"A.Q. Khan & Libya." Global Security.org, 2004. Internet: Link, accessed 23 Mar 2007.
Gurr, Nadine and Cole, Benjamin. The New Face of Terrorism: Threats from Weapons of Mass Destruction. New York: I.B. Tauris, 2002.
Sublette, Casey. "Could al-Qaeda Go Nuclear?" Nuclear Weapon Archive.org, 2002. Internet: Link, accessed 23 Mar 2007.