At normal consumption rates (i.e. non-hording, or panic buying), there is approximately three days of food in any given city or town.
Things go badly, mass prolonged civil unrest, our JIT/BAU system will fail.
IF people are in fear for their safety, those truckers are not going to be hauling food. Warehouse personnel, loaders are not going into the warehouses to fill the trucks with food and water. Lettuce pickers wont be going to work either.
For example look at the meat packing plants that shut down due to COVID.
And that is just the food industry.
What about public works? Some yahoo burns down a building and it just so happens to spread and destroy an electrical station, you think those repair men/women are going to go into a riot to fix it?
There would have to be a government response in order to get these things back up and running.
What would that look like? NG response? Martial law?
No idea.
I think it would look more like the Balkan war than a clear cut civil war. There are a lot of people out there with hate for the "others." And in this day and age, it could be race. It could be socio-economic class. It could be ideology be it Maxism, capitalism, socialism, etc. It could be Red vs Blue. It could be sports teams. Coke vs Pepsi. Vegans vs red meat eaters.
We are a nation that calls 911 when their Facebook page wont load. We, as a nation, are that stupid.
I know I would not want to be one of those NG units, ordered to go into a major metropolitan area to secure the peace.
Regardless, prep to get through the bottleneck.