The United States is moving to reduce its troops in Afghanistan, Iraq and Somalia over the next two months. As national security adviser to President Trump, retired Lt. General H.R. McMaster was at the center of the administration's military decisions. He joins Nick Schifrin to discuss why he's concerned about U.S. security strategy in Afghanistan and beyond. PBS NewsHour is supported by - https://www.pbs.org/newshour/about/funders