Now ABC's Barbara Walters is back tonight -- another exclusive interview this time secretary of state Hillary Clinton who's about to leave office. After traveling almost a billion miles to nearly 100 countries and everyone asking. Does she still dream of the presidency -- here right now. And that is a question -- as -- Clinton were -- done her time as secretary of state traveling the globe. We sat down together and I asked that question that's on everybody's mind. What's next. What most people last. -- It is when you consider running for president in 2060. We can't just like to make a declaration that. We could conclude doesn't in his. Well that would be fascinating to me as -- well as everyone else. It I've set I really don't believe. That that's something I will do again I. Am so grateful and experience of doing it before. But you know I I think there are lots of ways to serve so I will continue to serve what would it take to convince you to run and you know I just that's all hypothetical because right now I have no intention of running. We also -- after four years at her post as secretary of state what keeps -- McKnight what worries you the most. Iran. Iran worries me the most because it's not only. The terrible. Prospect that they might have a nuclear weapon they're already engaging in. Terrorism all over the world directly. Through their own agents. Using others like his -- -- what about here. Could well take -- share well remember they had a plot to murder the Saudi ambassador right here in Washington and so. When I look at the threat it's not only. This horrible. Prospect. Of what would happen to the world if they. Got a nuclear weapon but it's what they do every day. To try to. Project their aggressive. Image and attempt to you know influence the world. Secretary Clinton says they've heard pinging is to have peace in the Middle East she says there -- song much work still to do. And last but what -- -- she keeps saying she has no idea what she would do. But I've -- some good authority that there is someone who very much wanted to run for the presidency. Yes so -- the band of forest in her electric -- thank you so much Barbara Walters and want everybody to know. That -- ten most fascinating people. Including secretary of state Hillary Clinton will be airing tonight at 9:30 PM eastern time be sure to watch.