Jeff Sachs Warns "Nuclear War is a Real Threat" as Trump Threatens to "Totally Destroy" North Korea

On Tuesday, President Trump gave his first address to the United Nations General Assembly, boasting about the size of the U.S. military and threatening to "totally destroy" North Korea. "[N]uclear war is a real threat," says Jeffrey Sachs, leading economist and director of the Center for Sustainable Development at Columbia University. "It's not some idle imagination right now. You have two leaders-both seem unstable-yelling at each other. Both have nuclear arms."