Most of us are sensible enough not to live in cities. I’m not going to drive to the nearest city to “defend” it.
Besides, don’t cross US cops. They might not be allowed to save civilians and property but they WILL protect themselves.
Do need to stock up on more ammo, though.
Most of us who aren't retired live where the jobs are. I'm not driving 100 mile round trips five days a week. AS you said, ammo stocking.