Absolutely, the transnational or non-state actors are one of the current challenges.
I think what we need to do there is complement the existing regime, which is based on a state-centric approach, and we have to keep in mind that it's not like there are no problematic states any longer in the world. We need to ensure that remains valid but, at the same time, work again through cooperation to ensure that we're not giving openings for terrorist groups or other non-state actors to get their hands on WMD, for example. That's why the A.Q. Khan network has to be resolutely countered and investigated, and we need a strengthening of export control measures.
There are a number of international conventions—I won't go into them now—that have been prompted by this concern. The convention against nuclear terrorism was recently concluded. We've strengthened the convention on the protection of radioactive material to deny possibilities.
A lot of the work under the auspices of global partnership speaks to exactly these kinds of concerns. For instance, in the former Soviet Union, they used to power remote lighthouses with highly radioactive power sources. There is now a project under way to replace those with solar panels and other things, not that the material could actually be used in a nuclear explosive device, but it could be used in a so-called dirty bomb that could cause great consternation and casualties.
That's a very practical way in which you're just trying to keep a step ahead of those who might want to use this material for very nasty purposes.