Valiasr Square in Tehran, with a huge mural of captured US navy sailors in the background. Gloom and even dread can be felt across the city, where some blame not only the Trump administration but also their own leaders for the possibility of a violent conflict between Iran and the US. Photograph: Arash Khamooshi/The New York Times

It was supposed to be a regular weekly debate night for a group that meets to discuss movies in a middle-class Tehran neighbourhood. But on this parti(...)