Gun control is “collective punishment,” punishing everyone for the acts of a few. It’s considered a war crime under Article 33 of the Geneva Conventions. No civilian can be “punished for an offense he or she has not personally committed.” https://ihl-databases.icrc.org/ihl/WebART/380-600038
But it appears this applies to the occupying force in regards to the treatment of the civilians. The Geneva Convention probably doesn’t apply to a country acting against their own citizens.
But still, just being able to say, “Under the Geneva Convention, this is considered a war crime” can be powerful in a sound bite environment. Or, if Civil War II were declared…—Joe]