Weber's Theory

In the last week or so, I think I've heard the definition of a "state" as and entity that claims a monopoly on the legitimate use of violence within a given area. This grouping of words seemed to be more than a coincidence...and that's what Wikipedia is for. It's called Weber's Thesis. It's brought up frequently in relation to the Iraqi situation and how the forces of violence seem to be aligning along tribal lines instead of in support of a central government. It seems to be a pretty solid theory to me: name one stable country with two armies.