A while back I pondered the question of identifying the attackers in the case of a covert nuclear attack (i.e., a suitcase nuke, or one delivered via boat or van).

I never got a good answer as to whether or not we'd be able to identify who did it and where the nuke came from.

Via Gene Healy, here's an article in the Journal of Homeland Security about that very subject.

On the attribution of a nuclear attack:

If the nuclear event is large enough, or not muffled by the overburden of a building, it will be seen by the nuclear detectors that ride on some U.S. satellites. We will have some sense of the scale of the event and perhaps a notion of the sophistication of the device, and we will certainly know where to go to acquire samples. It is not clear at present that these detectors trigger a forensic process. Once on the scene, samples of debris from the explosion can be acquired for analysis in the field or returned to established and trained laboratories for analysis. However, the authority to access the site will need to be established with those operating the consequence management activities—and at a time of frantic humanitarian, social, and political activity.

Yeah, in other words, a city is basically going to be a giant, radioactive slagheap, and those that survived along the blast radius are going to be burned, irradiated, screaming, and bloody. Not your typical crime scene.

The standard techniques of mass spectrometry and possibly gamma spectroscopy can be used to determine the original isotopics of the nuclear fuel, the efficiency of the fuel burn in the detonation, and possibly other information such as materials in the device itself.

Okay, so let's say we know the nuclear material came from a uranium mine in a former Soviet republic. Do we then nuke them?

I'm not exactly confident in our ability to identify the origin of a covert nuclear attack. If somebody fired a missile with a nuclear warhead? Yeah, then we'd know who the attacker was. But if a nuke were smuggled in? Hell, we can't even find who mailed anthrax to our news outlets and Congresspeople. We're going to be able to track down the perpetrators of a nuclear attack when all that's left is a melting, radioactive pit?

The problem is sufficiently daunting that no confident statement can be made at present about the likelihood of success.

Yeah, that's what I figured. They say they're working on it, though, which is good. But I wouldn't be too optimistic about their chances.