Zombie apocalypses essentially. Only ones that might survive would be rural areas as long as they could defend it. But even then, if transportation stops one better have some good old fashioned means of defense.
The problem with all survivalist scenarios is they only last some limited time.
You cut off oil to the US refineries, or wipe out the refineries themselves, it is about the closest thing to forever as you can see.
Having a gun to defend . . . what? Food runs out. 2000 calories/day. No tractor fuel to plant more.