Thinking about the rise of Islamic State, Matt Ridley reminds us that the origin and defining characteristic of all government is that it is an organisation with a monopoly on violence (emphasis mine):

The deal implicit in being governed is at root a simple one: we allow the people who govern us to have an exclusive right to commit violence, so long as they direct it at other countries and at criminals. In almost every nation, if you go back far enough, government began as a group of thugs who, as Pope Gregory VII put it in 1081, “raised themselves up above their fellows by pride, plunder, treachery, murder — in short by every kind of crime”.

And from this follows a disgusting truth:

Should Islamic State’s caliphate endure, it is a fair bet that it will eventually become a bureaucracy peopled with functionaries rather than assassins.

Because most if not all states inherit from a similar dark past. Make no mistake:

… the monopoly of violence is always there even in western society. If you doubt it, try not paying your taxes and see what happens when you resist arrest.