Saving lives in dire times — and the ethics of working with aggressors

As the former head of humanitarian relief for the United Nations, Mark Lowcock has seen the best and worst of humanity. It was his job to coordinate aid and rally international support for people caught in the world's most desperate crises. Now that he's left that post, he's reflecting on what he's learned in a new book called Relief Chief: A Manifesto for Saving Lives in Dire Times.