Granted, there are simplistic terrorist means to inflict damage .. but the terrorists desire is for a ''high impact" hit on America .. could you imagine the rejoicing in Muslim terrorist centres if they managed to pull off a nuclear hit in the heartland of America??
Give me a list of weaponry that has not been captured and used against it's makers and builders .. and the list wouldn't run to three headings ..
I find the following gentlemans site, quite fascinating, too ..
http://www.mmmfiles.com/archive/pantex.htm
Particularly, the part about an estimated US$300 Billion just to clean up the radioactive waste generated from plutonium production alone ..
The construction and operation of nuclear devices seems to be quite within the realm of terrorists .. who can buy items needed to repair PC's .. and nuclear weapons .. off many of the willing shadowy worldwide sellers who can supply them with all the technology they need ..