Jonathan Powell is CEO of the conflict resolution charity Inter Mediate and has made a career talking to some of the world’s most dangerous people. He was U.K. Prime Minister Tony Blair’s chief of staff, chief negotiator in the Northern Ireland peace process, and the author of “Talking to Terrorists: How to End Armed Conflicts.” In a frank, thoughtful and occasionally tense conversation with New Lines Magazine's Faisal Al Yafai, they discuss why he advocated talking to the Taliban 10 years ago; the missed opportunities of the war on terror; what it was like negotiating with the IRA; how history will remember Tony Blair — and whether he has sleepless nights over the invasion of Iraq.