The Comoros is a volcanic archipelago off Africa’s east coast, in the warm Indian Ocean waters of the Mozambique Channel. The nation state’s largest island, Grande Comore (Ngazidja) is ringed by beaches and old lava from active Mt. Karthala volcano. Around the port and medina in the capital, Moroni, are carved doors and a white colonnaded mosque, the Ancienne Mosquée du Vendredi, recalling the islands’ Arab heritage. It became part of the...