The first part of my testimony suggests that the Islamic Republic of Iran stands at a dangerous nexus of deep hostility towards the United States, pursuit of weapons of mass destruction, and international terrorism. It is only prudent that we consider the risk that Iran might one day undertake or sponsor a WMD terrorist attack against the United States, and I provide several examples of scenarios for such an attack. 

 To help assess whether and under what circumstances Iran might engage in such behavior, I then propose a framework that considers on one hand possible impediments, and on the other hand possible enablers or inducements, to Iranian WMD attack on the United States. Finally, I suggest a number of implications of this threat for U.S. national security planning.