

The only scenario where US territory comes under occupation is one where the US is in complete and total anarchy, where their Navy isnt stopping European, Chinese, or Russian forces from landing on its own shores. Any other scenario, North America is safe from Overseas invasion.
even in a war scenario, Mexico and Canada aren’t going to try to occupy American territory.
I suppose the only other scenario would be if there was a successionist movement that tried to leave the Union.
Vigilantism is on the rise regardless, Either because the police are incompetent / carefree about the complaints. or because individuals are overzealous, dont undrestand or agree with the law, and decide to cosplay as the punisher.