The Smallest Minority has a powerful piece on the nature of freedom, and the slim, slim thread from which our liberty hangs today. The simple fact is that a civil war is no longer a serious possibility. We are not geographically divided sufficiently for such a thing to take place. There is at least some urban-rural split; that is exactly the kind of problem that a local-government system should address. Unfortunately, our system of regional government no longer functions as designed; both rural and urban governments are subordinated to the rules at the federal level, and few of the busybodies are willing to settle for rules enforced only at the local level.
So if there is a civil war, it would be the cities versus the countryside, but even that is awkward.
That difficulty is I think, a testament to the wisdom of our founding fathers. It is very hard for the US to fight a civil war against itself. But the strain is definitely showing.
I've often said that the US begin life as a frontier nation, on the edge of civilization. It was an environment that enforced self-reliance, independence, and responsibility. We had entire generations of people who could live under a government in a city or town if they chose, but who also had the choice to go off in the wilderness on their own.
That choice is no longer effectively open to us, because the federal government has abandoned the enumerated powers doctrine and seeks now to regulate almost everything that can be regulated, and there is no place for those who do not consent to this form of government to go. We are, in short, cornered wolves -- with no place to run, the teeth are starting to show. And the sheep are no fonder of our presence than we are of theirs.
Is there a solution? Yes, but that solution has gone out of fashion. Limited federal government, with most powers residing in the states, or even the county or city level, allows for individuals to live out their lives in a regulatory environment -- or perhaps more pointedly, a lack of regulatory environment -- which they choose.