As thousands of Iranians mourned the death of General Qassem Soleimani, President Trump continued to verbally attack the country on Twitter. He warned the U.S. was ready to attack if Iranian leaders choose to retaliate by targeting U.S. citizens or bases. CBS News correspondent Marc Liverman reports on the latest, and Lina Khatib, head of the Middle East and North Africa Program at Chatham House, joined "CBSN AM" to discuss.