World News National Obama Addresses World Leaders At Final Nuclear Security Summit 4:23pm April 01, 2016 by Scott Horsley U.S. World National Security Share URL copied to clipboard! Copyright 2016 NPR. To see more, visit NPR. 300x250 Ad More All Things Considered Music & Culture Podcast explores the changing music scene in Austin, Texas National Science Solar storm disrupts communications by Geoff Brumfiel 300x250 Ad Support quality journalism, like the story above, with your gift right now. Donate