Civil Wars

I wrote a brief post Monday about the cause of war. So you won't have to re-read it, I'll remind you. My own dumbass view is that wars generally come about because (a) resources are always scarce, and (b) we as humans are biologically inclined to take this as a reason to fight -- we are pack animals inclined to us-against-them attitudes.

Civil wars, though, are especially confusing and the question of how they come about is fascinating.

By definition, a civil war is one between "us" and "us," not "us" and "them." Or, to put it differently, at some point a community because so badly split that some of the former "us" has now become a "them."

Is there anything we can say in general about why this happens? Anything that would cover England under the early Stuarts as well as the United States in the time of weak Presidents and strong Senators?

I'll just leave that now for the pondering.