Today in Moscow, the U.S. and half a dozen other countries are holding a summit on the best way to end the war in Afghanistan, launched by the U.S. nearly 20 years ago. President Joe Biden recently said it would be "tough" to pull American troops out of the nation by May as planned by the Trump administration. How does that affect the prospects of peace in the country? Nick Schifrin explores. PBS NewsHour is supported by - https://www.pbs.org/newshour/about/funders