Who would rule Iran if the Islamic Republic falls?

As anti-regime protests continue to spread across Iran and questions swirl about the durability of Supreme Leader Ali Khamenei’s rule, a central question looms: Who would actually take power if the Islamic Republic were to collapse?

The answer, according to regional experts and Iranian opposition figures, is far from clear. It may depend less on ideology than on how the regime falls and whether Iran’s security forces fracture or hold.

Behnam Ben Taleblu, a senior fellow at the Foundation for Defense of Democracies...