Without the background of Zengid politics or Islamic schisms, and without the context of the conflicts of Christendom, it is impossible for the reader to make real sense of Saladin, or a real king of Richard.

ECONOMIST: The medieval crusades

The schisms of ethnic group or tribe can often define attitudes in Afghanistan.

BBC: How Afghans will view Kandahar killing spree

Permanent alliances put strains on existing domestic schisms along ethnic, ideological or religious lines.

FORBES: Benjamin Netanyahu Vs. Barack Obama, Part One