This tale is disturbingly possible. It is an American Redoubt, militia, survivalist type of story. That’s the focus, but the story is quite short. The author was more interested in getting the truth, as he sees it, to his readers [assuming it’s a he, but she’s not]. But for a scenario which might happen as we wait for the Lord to return, this is a fun ride.
For a short story, the characters are fairly well developed. Plus, they are likeable! That’s a rarity these days. The bad guys are a bit stereotypical, but then stereotypes happen because they are common.