Last month, the three arrested activists had joined two like-minded figures—former Deputy Interior Minister Mostafa Tajzadeh and the Nobel laureate Narges Mohammadi, both in prison—in calling for a democratic transition and free elections for a constituent assembly. In an interview with BBC Persian, Mahmoudian called on Supreme Leader Ali Khamenei to resign. Hassan Asadi Zeydabadi, a lawyer who represents Rabbani and Momeni, told me that his clients were most likely arrested because they advocated for Khamenei’s dismissal and because “the regime wants to prevent the formation of a national opposition inside the country.”