That's a big fear for me. Just look at different African nations. You basically have soldiers battling on different sides and 95% of the population that aren't soldiers are caught in the crossfire...and caught in the ugliest possible way: raped in mass, pillaged, houses/villages/infrastructure destroyed
over and over again.
African models to not tend to match US very often on much of anything.
Only thing really close to that is the Soviets coming into Berlin, at the close of WW2.
A modern day example closer to home is inner city drug gangs. 98% of the population is caught in the crossfire while the young teens and 20-somethings battle it out for turf and money. Today it's drugs. Tomorrow it's drugs, food, fuel, medicine. The black market is poised to be *the* market and corruption will rule the day from the top elite (as it does now) to the bottom.
The only thing keeping the " inner city drug gangs " safe and operating is the law. Most of the folks in the US do not really tolerate that -- only the law does. And as most folks in the US tend to follow the law, the gangs are safe for now.
Absent the law, the whole game changes. Historic models of the US come much closer to the Klan = Taliban, or even the "posse" model. Hard part tends to be getting the Klan = Taliban shut down after the determined "bad guys" are exterminated.