Fox News chief foreign correspondent Trey Yingst breaks down the significance of the IDF’s killing of Hezbollah chief Hassan Nasrallah, the possibility of an Iranian retaliation, and previews his new book ‘Black Saturday.’ Fox News chief foreign correspondent Trey Yingst breaks down the significance of the IDF’s killing of Hezbollah chief Hassan Nasrallah, the possibility of an Iranian retaliation, and previews his new book ‘Black Saturday.’