On Sunday afternoon, protesters in Islamabad pressed shoulder to shoulder, most of them dressed in black, and chanted slogans that rippled through the crowd. “Death to America, death to Israel,” they shouted in unison. Among them was also Kazim Hussain, who clutched a portrait of Ayatollah Khamenei. The student, also an activist affiliated with Shia group Imamia Students Organisation (ISO), believes that the crisis unfolding in Iran was not a distant geopolitical conflict playing out beyond Pakistan’s western border. For him, it is deeply personal and emotionally moving.“This is not just an attack on Iran. It concerns all Shia Muslims,”...