Biden announced that he wants to have U.S. troops withdrawn from Afghanistan by Sept. 11, 2021, two decades since the terrorist attacks on the Twin Towers and the Pentagon. What are the geopolitical ramifications of pulling out, and what do veterans who served there have to say about it? On today's show, David Sanger, White House and national security correspondent for The New York Times, talks about how world leaders and national security experts are reacting to the news.