I love how people call this "alarmist," and are quick to deride it (which is somewhat understandable given the source), when the fact of the matter is that it is only a matter of time before a nuclear device is detonated on US soil. It may be "alarmist" now (in that it might not happen in the immediate future), but in the years to come it will be a tragedy, and all the smartasses who are so quick to mock reports like this will feel like assholes for having ever opened their mouths. Sorry for the tone, but seeing as how I live in NYC, and how it's likely to be my family and I who are incinerated in an eventual attack, I get kinda pissy when people try to downplay the gravity of the situation.
The only way such a situation could be avoided would be to fundamentally change the way our government (and the corporations who run our government) does business abroad in order to address the oftentimes legitimate grievances other factions/nations have against us (i.e., a nation which acts justly in all its dealings does not have many enemies), and also to completely lock down our Northern and Southern borders and inspect every ship coming into port and every plane departing from foreign soil for our nation's airports. Since that's not going to happen (though it could-- and it should have-- if the government was truly serious about protecting our citizens from terrorism; the cost would have likely been less than the Iraq war, anyway). But since neither "remedy" is going to be implemented (either a change in the character and policy of our nation or tighter border/port security), a nuke is inevitable. I really wonder what the people who believe that it's not are thinking sometimes...