US gun ownership
The historical mindset is that the US was founded in armed rebellion against His Brittanic Majesty, and we need to remain well-armed should "the gummint" become too oppressive. The possibility that such an uprising would be winnable, even with the level of weaponry available to the average USian, is dubious at best.
The arms industry has peddled their wares with a mix of defending one's home (primarily against "the Other"), appealing to the above fantasy and down in the fine print, the legitimate uses of hunting and target shooting. Given the number of weapons at hand in the US, it can honestly be said that 99.9999% of gun owners are harmless, even the doomsday preppers stockpiling weapons afraid that The Aforesaid Gummint is coming in their Black Helicopters to seize them. That said, the loopholes in the existing rules for gun sales allow people who have no business owning firearms to do so, with the disastrous results we've seen over the years. Closing these loopholes up, including 'red flag' laws for legitimately disarming people under domestic restraining orders, judicial psych eval, etc would hopefully at least slow the rise in such tragedies.