At the start of the 21st century, several groups began efforts aiming not just to control nuclear weapons but to eliminate them altogether. The so-called Gang of Four, William Perry, George Shultz, Sam Nunn and Henry Kissinger, wrote numerous powerful op-eds, urging us to work towards a world without nuclear weapons. Bruce Blair turned from academics to founding Global Zero, dedicated to the same goal. And a coalition of activist groups formed the International Campaign to Abolish Nuclear Weapons, ICAN. In 2017, the United Nations adopted the Treaty on the Prohibition of Nuclear Weapons, and ICAN was awarded the Nobel Peace Prize.