Why New START expired now

The last remaining US-Russia nuclear treaty that put limits on nuclear arsenals, the New START, expires today. Experts warn that without a new treaty, it raises the risk of a nuclear arms race in an increasingly volatile world, We speak with Thomas Countryman, Board Chair of the Arms Control Association, and a former U.S. diplomat who served as undersecretary of state for arms control and international security, and Matt Korda, the Associate Director for the Nuclear Information Project at the Federation of American Scientists, who's tracking nuclear arsenals and trends.