As the United States seeks to deter Iranian aggression in general, and its use of NBC weapons in particular, it is prudent to try to understand the legal and moral traditions that provide a context for Iranian decisions about war. Shiite tradition differs from Western "just war" tradition. While Iranian Shiite interpretations of Islam forbid declaration of offensive religious war, there is a standing authority and indeed an obligation to use force to defend Islam. Such use of force is not considered to be offensive since the persecution of believers is the same as an attack. A jihad (holy war) could thus be readily justified as "defensive." This might mistakenly lead some to believe that Iran would only fight 'defensively' in the sense that it would not strike first and would see NBC weapons strictly as weapons of last resort. However, as a practical matter, virtually any act contrary to Iran's interests taken by the West (such as the U.S. embargo) could be defined by the mullahs as "persecution." Further, while Western just war tradition obliges restraint in the prosecution of war, particularly the requirement that combatants limit, to the greatest degree possible, the impact on non-combatants, once a defensive jihad is declared against disbelievers, there need be little restraint in its prosecution. Employment of NBC weapons, even against civilians-let alone the military-could be justified. Thus there are few apparent moral or religious impediments should Iran choose to employ NBC weapons against the United States. Assessments which fail to recognize that the Iranian justification for war has a significantly lower threshold than that established by Western just war doctrine could be dangerously misleading.
Strategic Forum no.110 (April 1997)