Trump calls on Arab world to unite against extremism

President Trump on Sunday called on the Arab world to show unity and partner with the U.S. to combat extremism and terrorism. The speech was held in Saudi Arabia to a summit of leaders from 50 Arab and Muslim-majority countries. Gary Sick, a senior researcher scholar at Columbia University, and Farah Pandith, a senior fellow with the Council on Foreign Relations, join Alison Stewart with more.