U.S. official says Iran engaging in ‘nuclear blackmail’

Iran announced its partial withdrawal from a 2015 nuclear treaty on Wednesday, citing the failure of other member nations to deliver promised economic relief after the U.S. pulled out of the deal a year ago. What does the development mean for the relationship between the U.S. and Iran, already tense? Judy Woodruff talks to Brian Hook, the State Department’s special representative for Iran.