In the years ahead, Israel could face the growing prospect of WMD terrorism – i.e., attacks involving chemical, biological, or even nuclear weapons. In this connection, it is vital that Israeli officials do their utmost to prevent perfidious enemy manipulations of humanitarian international law. This is especially urgent with regard to enemy use of "human shields," an illegal form of military deception that could be used to deter Israeli retaliation. Perfidy can originate with both state and sub-state foes, and could conceivably involve primitive nuclear devices such as "dirty bombs" (weapons that do not involve genuine chain reactions, but instead attach conventional explosives to fissile materials).