The Hadramis of South Yemen and the emergence of their diasporic communities throughout the Indian Ocean region are an intriguing facet of the history of this region’s migratory patterns. In the early centuries of migration, the Yemeni, or Hadrami, traveler was both a trader and a religious missionary, making the migrant community both a “trade diaspora” and a “religious diaspora.” This tradition has continued as Hadramis around the world have been linked to networks of extremist,...