How Russia could spark a new nuclear arms race

Since the war began in Ukraine, Vladimir Putin has threatened to use nuclear weapons.  Now, he's backing out of a nuclear agreement with the United States which limits the amount of nuclear warheads both nations can stockpile.  But why?  Today, the former US chief negotiator of New START on why Putin's decision could spell the beginning of a new arms race.  Featured:  Rose Gottemoeller, former NATO deputy secretary and former chief US negotiator, New Strategic Arms Reduction Treaty