The 2017 Nobel Peace Prize winner wants to ban nuclear weapons. Here's why the US is opposed.

The 2017 Nobel Peace Prize winner wants to ban nuclear weapons. Here's why the US is opposed.  Washington Post Nobel Peace Prize winners warn the world is 'one tantrum away' from nuclear crisis  Business Insider Nobel Peace laureates: Nuclear war is 'one tantrum away'  USA TODAY Winning the Nobel peace prize confirms my life's mission to help end nuclear weapons  The GuardianFull coverage