weapons on alert. we know he has smaller, more tactical, weapons. what is the probability that putin could use some kind of nuclear weapon? >> well, we are watching this extremely closely and obviously the escalation risk with a nuclear power is severe and it is a different kind of conflict than the conflicts the american people have seen over the years. president biden has to take that responsibility extremely seriously, even as we redouble our efforts to support the ukrainians. as things stand today, the united states has not adjusted our nuclear posture, but it is something we monitor day by day, hour by hour, because it is of paramount priority to the president. >> that sounds like you're concerned. >> any time you have a nuclear power fighting in a conflict zone in europe near nato territory, of course, we have to