Islamization advanced largely by building parallel civil-society institutions that supplanted secular ones.

Evidence

In most countries a central element of Islamization was the development of Islamic social organizations and the capture of previously existing organizations by Islamic groups. Islamists paid particular attention both to establishing Islamic schools and to expanding Islamic influence in state schools. In effect Islamic groups brought into existence in Islamic “civil society” which paralleled, surpassed, and often supplanted in scope and activity the frequently frail institutions of secular civil society. — Samuel P. Huntington, The Clash of Civilizations and the…, 305

Categorization

• XREF: Parallels the social-capital and trust literature about institutions substituting for state enforcement — the Milgrom and Bernhard pieces on extralegal orders.
• STORYSTEM: A fictional parallel-state: a banned political movement building cradle-to-grave services to win legitimacy — strong worldbuilding engine for a novel about a society with a failing state.