party to any kind of lasting peace but the bottom line is we can't be the guarantees of prosperity in an ideal situation in afghanistan. look, when i was there five years ago in 2014 as a lieutenant, i thought i was among the last u.s. troops to be there and now, we're in 2019, you can be old enough to enlist and not been alive when 9/11 happened. the departure has to be accelerated and we have to do it in a context that makes sure that we are going to be protecting the homeland so that people don't get sent over there again in the future. >> christina myers asked what is the biggest regret in your professional life, something you wish you could go back and change your if i knew then what i know now moment? >> well, early in my professional life i've turned down a job offer for the obama for senate campaign in 2004 because i had a chance to work for john kerry and it didn't