because they have the financial means now. that takes the most technical expertise and feasibility. it would be very hard for them to do. biological terrorism is the simplest. if they could find somebody with any knowledge of working with these types of biological terrorism weapons it's very simple to produce. can be done in a kitchen. they don't need an extensive laboratory to do it. i don't know that we have any direct threats from isis about that yet, but i imagine it's something they're pursuing great greatly as opposed to small pox which we know is a holy grail for them. colonel, you concluded anthrax poses the greatest threat to the united states. why? >> well, it's a very likely threat and a very persistent threat. we don't know how to clean it up frankly. and we know that we capture add computer from isis last year that had information on it about using plague as a weapon which