[user104658]

Originally Posted by bitontheslide

we are at far greater danger of russia lobbing a barrage of nukes at us at the moment, so it's not particularly high on my agenda. Also, it's easy as pie to track anyone with nuclear material

I reckon a terrorist dirty bomb is slightly more plausible than a barrage of Russian nukes, on balance.

The main difference is, the Russians could do it at any time but don't, whereas a terrorist cell WOULD do it at any time but can't.

I feel like the means to do it for the latter is more likely to change than the reasons not to for the former.