One paradox of these kind of events is that normally the panels you're most interested in attending mostly feature experts telling you things you already know -- these, after all, are the issues you're interested in. But at a panel on nuclear proliferation, Bruce Blair from the World Security Institute told me that far more nuclear weapons than I'd realized -- about 2,500 -- are still on hair-trigger status in the United States and Russia. That means these weapons could be launched within minutes with no advance preparation on the part of the White House or the Kremlin.

It's a remote possibility, of course, that those weapons would be launched on accident or in some fit of madness from Bush or Medvedev. But considering the extent of the downside risk, and the lack of big-time US-Russian tensions this seems crazy. Surely we could dial this back such that in case a crisis developed we could consider shifting the weapons onto this kind of status.