Former president george w. bush returned to washington last night. in a rare speech, he warned of the dangers of isolationism. listen to this. >> very important for our fellow citizens to remember these words from winston churchill. america is in dispensable for the world and the dangers of isolation loom. people of the united states cannot establish world responsibility. i wholeheartedly agree. >> joining us now, former defense secretary under president obama, ash carter, the author of the forth coming book "inside the five-sided box" to be released next year. always good to see you, sir. tha...