A reader writes:
You begin your post by writing the following:
"I take as a premise that there is a group of religiously-motivated terrorists attempting to inflict massive damage on the West with minimal resources and maximal impact. I consider this, after 9/11, to be the pre-eminent challenge of the time. And the danger of their acquisition of very seriously destructive weapons is easily the most pressing threat we face."
Perhaps re-thinking the war begins with a more careful examination of this very premise. For instance, there are those who believe that 9/11 was a "perfect storm," a confluence of events that included incompetent airline security on the ground and in the air, an administration who was warned of an impending attack and ignored it, and a number of "what could go wrong, did go wrong" scenarios. Some would suggest pulling something off of that scale is immensely difficult and unlikely to happen again..
Then there have been numerous intelligence reports that suggest that, within the U.S. borders at least, the threat by religiously-motivated terrorists is surprisingly small. Any cells that have been disrupted turned out not to be anything of much seriousness (remember those who stated as an "aspiration" that they'd like to blow up the Sears Tower?).
Now, as an American-Israeli whose entire families live in Israel and New York, I'm in no way discounting the threat of terror. It is real. It is dangerous. My family and I are all too familiar with it, we've been living with since long before 9/11.
What I am suggesting is that where you've gone wrong is that you haven't done enough to examine the PREMISE of your question. Is it a real danger that terrorists can get ahold of seriously destructive weapons? If so, what is the evidence for that? Where would they get these weapons? And how would they use them? What are your sources of information that confirm, based on real evidence, that this is an impending possibility?