i'm mary louise kelly. i've been covering some of this for npr, the other npr. i wanted to ask, as we gear up for this big summit here, president obama is about to fly to prague to ink a new arms deal with the russians. i wonder if i could get any or all of you to weigh in with your assessment how significant that is and how it plays into the broader effort that is going to get underway here given, as you've all been saying that's an effort focusing a little bit less on superpower arsenals, and more on rogue states and nuclear terrorism? >> i think for the first time, with the immediate information that we've been getting on the nuclear posture review and the new reset, if you will in u.s.-russia relations you see certain sort of points in terms of orchestrating an agenda that will, that will turn the u.s. position, if you will, vis-a-vis the international community, to a more positive, more positive prism from the outside looking in. of course the posture view, i know you didn't ask about that but i think you have to observe that from two levels. how will the i