To me it's always seemed like money grows from the barrel of a gun. Detaching money from military power sounds wonderful but it makes no sense to me. It seems to defy the very basis of what money is. Tokens handed out by warlords. Only stretched out over such a long time that it isn't obvious any more. Obviously I am neither an economist nor a political theorist.
I always figured that 'naturally arising' currencies, like gold and cigarettes, have two key properties: a) perceived inherent value (e.g., gold by long tradition and whose origins are lost to history, and cigarettes because people want their fix) and b) natural limitations on quantity (and counterfiting: gold has known density, and a fake cigarette is apparent as soon as you try and use it).
The purpose of the gun, it has seemed to me, is to get around the fact that fiat currencies have neither of the above properties, but that both can be enforced to some degree.