Donald Trump embraces disruption and unpredictability, but what does that mean for America's national security and foreign policy? At first glance it seems to herald a new era of confrontation, from the Korean peninsula to the Mexican border, but are there limits to the President's break with convention? Hardtalk’s Stephen Sackur speaks to veteran US diplomat and adviser to a host of Republican presidents - John Negroponte. Does this presidency mark a permanent shift in America's global role?(Photo: John Negroponte speaks at the 2016 Concordia Summit, New York. Credit: Paul Morigi/Getty Images)