Iran is in the grip of its most intense unrest in years with protests spreading across the country and Donald Trump vowing that the US will defend Iranian protesters - prompting Tehran to accuse him of psychological warfare. 

What began in Tehran’s bazaar over soaring prices and a collapsing currency has spread across 27 provinces, with inflation above 50% and a government struggling to contain anger over corruption and falling living standards.

Human rights groups say dozens have been killed and more than 1000 arrested, as police move into universities and the judiciary warns that any period of concessions is over. 

So who will back down, the protesters or the regime? And what does this mean for the future of the Islamic Republic of Iran and it’s supreme leader Ayatollah Ali Khamenei?

On this episode of The Fourcast, Matt Frei is joined by Professor Ali Ansari, a leading voice on Iran’s modern history, and Doctor Sanam Vakil, director of Director, Middle East and North Africa Programme at Chatham house.