Iran's revolutionary regime is built to resist shocks

The assassination of Iran’s Supreme Leader Ali Khamenei was a jolt for Iran, but its political system is built to sustain abrupt change. Also, a look back at the Russian government's troubled history with high-profile poisonings. And, how Israelis are celebrating Purim underground this year. Plus, how the European Union is responding to the US and Israel's war with Iran.Photo credit: Vahid Salemi/AP