I largely agree with Mike’s assessment of what we should take away from the NIE. One might argue that for a weapon delivered by aircraft, a design that didn’t require symmetrical explosives and precise electronics would suffice. But if you wanted to put the bomb on top of a missile, yes, you’d need that even for a uranium-based bomb.

I should emphasize, though, that a terrorist group would not need to meet the same technical demands, especially if it used uranium in its weapon. (And it would not use a missile for delivery.) Too many people confuse the two and end up overestimating the demands on a terrorist group.

That said, many of the same themes apply. In particular, putting plans into operation is harder than just describing them. That’s an insight that’s clearly influencing projections of how quickly the enrichment program will progress. This is especially true for the State Department’s dissent on the timeline for the enrichment program.

What about state transfers to terrorist groups? I agree with Bill that they are unlikely, primarily for the second and third reasons he gives. (I’m not as convinced by the scarcity argument – a state with ten weapons probably wouldn’t miss one too much.) Still, I wouldn’t rule it out. States can take big risks, like North Korea did when it started reprocessing plutonium a few years ago. Yes, the United States hadn’t explicitly threatened to bomb it, but the possibility was still there. What I worry about more, though, is that someone who didn’t have national interest at heart might subverting state controls over weapons or materials. In that case, the deterrence and scarcity arguments wouldn’t hold up. But all that said, the bigger danger from a future Iranian weapon is not that it would be transferred to terrorists, but that it would secure a loathsome regime and could lead to accidental regional war.