Protests have rocked Iran, a brutal crackdown is under way and Trump has threatened to intervene. Ellie Geranmayeh on a dangerous moment for the country’s leaders

U.S. President Donald Trump issued a new warning to Iran's leaders on Friday as videos showed anti-government protests raging across the country.

The exiled son of Iran's last shah, who has emerged as a prominent voice in the fragmented opposition, made his strongest call yet for the protests to broaden.