Thanks to Matt Bunn for keeping the dialogue on Michael's book moving forward. It's hard to know what to add, as Matt's bottom line makes eminent sense -- nuclear terrorism is a real threat, and we need to act urgently to address it. And I also agree with Matt that the vast bulk of our efforts should focus on preventing terrorist groups from getting bomb-making materials in the first place.

But I would still like to add a few points. First, I'm not sure, as Michael suggests, that successful terrorist organizations are "averse to failure," and that this may reduce their incentives to seek and try to use a nuclear weapon. On the recruiting front, the very audacity of such an effort might appeal to a certain sort of potential terrorist, whether or not it works on the first attempt (assuming, as Matt does, that there will be more than one).

I am inclined to think that, as Michael also notes, that "there may well be capable groups out there that are not averse to failure."

But "fear of failure" isn't the only important impediment Michael cites. Wariness about recruiting outside technical experts for fear of exposing a nuclear plot is one such example. The many steps involved, from getting the nuclear material, to fashioning the bomb, to successfully smuggling it into the target country, presents a whole series of obstacles.

While I am more inclined than Michael is to think that there may be terrorist groups that are willing to pursue a nuclear weapons project without being deterred by any great fear of the consequences of failure, I am less convinced than Matt regarding the level of probability of a successful terrorist nuclear initiative. The OTA study on what it would take a small group of individuals to build a bomb is a worst case scenario; and the fact that in the thirty years since that report was released no group has done so would seem to favor Michael's argument that it's not as easy to get the bomb as some people think.

Matt's suggestion that one of the real problems is that leaders like Pervez Musharraf aren't scared enough about the prospects of terrorists getting a nuclear device needs to be qualified, in my view. It's hard to plum the depths (if there are indeed "depths") of the minds of folks like President Bush and Vice President Cheney to tell whether they sincerely believed that Iraq could get a nuclear weapon and share it with terrorists; but at least at a point in time, their use of this assertion seemed persuasive to enough Americans to help build support for going to war with Iraq.

So, I think there may be a fear among the general public that terrorists could get a nuclear weapon relatively easily; but I think it is coupled with serious doubts about whether anything can be done about it, and a lack of knowledge regarding what the most effective measures would be in attempting to prevent terrorist acquisition of nuclear weapons. So, if nothing can be done, why dwell on the threat?

Finally, neither Michael nor Matt -- at least in these posts, which granted are far from definitive given the complexity of the problem -- discuss the role of politics. Why has it been so hard to get U.S. administrations to radically increase the effort put into policies designed to lock down or destroy loose nuclear weapons and bomb making materials? Is it just a lack of knowledge, or are other factors at play? In the U.S.-Russian context, how do other aspects of relations between Moscow and Washington either promote or interfere with urgent action on this front? Does the perception of U.S. nuclear dominance make it harder to get countries other than Russia to accept U.S. assistance in securing their own nuclear materials, as counterproductive as such a stance might be?

I'm not suggesting that I have answers to these questions, but I'd like to see more discussion of them as an important part of crafting a policy of preventing nuclear terrorism.

I'm not sure if I'll get to weigh in again or not, but if not thanks to Michael and Matt for a great discussion.