I see the coming "civil war" being very different than the last one. It will come about due to further societal breakdown - simply more, much more, of what we already see in so many cities now. Food, shelter and energy shortages will get worse and those dependent on government largess and services, and with no life survival skills of their own, will become increasingly desperate. The country will become a hodge-podge of "pockets of anarchy and decay" surrounded by areas where more resilient, more prepared, and better armed people will manage pretty well. The fighting will be limited to defending the viable areas from the starving scum that venture too far from their decayed cities in search of food etc.