Islamic governance once rested on tribal-group trust.

Evidence

The system was once based on trust between members of tribal groups; on fear of authority on the part of urban populations; and on a shared reverence for a Revelation, which restrains the arbitrariness of the urban state firstly by specifying limits to what it may do, and secondly by providing the means for activating opposition. — Diego Gambetta, Trust - Making and Breaking Cooperative…, 2059