Since 2002 Sunni jihadi groups like Jaysh al-'Adl have been active in Iranian Baluchistan, yet the region remains relatively stable. Dudoignon's book shows that the key reason for this is Tehran's cultivation of good relations with Sunni ulama in the Sarbaz area in Baluchistan, a policy that began after World War Two.

Educated in the socially conservative south--Asian Deobandi school of Islam, the Sarbaz ulama have conspicuous transnational connections and yet have been valuable to Iran's governments. They were recruited by the Pahlavi Shahs as a bulwark against Soviet influence, and they...