There's also other challenges out there as well, but in terms of urgency, I'd say North Korea. In terms of power right now, it is probably Russia and the nuclear threat. And in terms of long-term political will, it's China.
But China does not have to be a threat. We can find a way to work together with China. We're two nuclear-armed superpowers and we're going to have to learn how to manage our relationship, and I do believe we can do that.