That must be why there are so many homicides with other weapons in Western Europe and most of Asia.
I could never find a good response when my rational argument is met with an off-hand snark. And yet something should be said to avoid the perception that it was a valid counterpoint.
One option would be to point out that there are multiple factors at play, other differences between those countries than just gun ownership. That study after study linked in the post before show no correlation, no meaningful impact of gun ownership. That there are causes of crime that explain reality much better, like family structure.
Other would be to mock. "Sure, let's ban all the guns, jail all the blacks, and live in a crime-free utopia. Oh, and maybe nuke Detroit or New Orleans while we're at it. After all, nothing gives a better picture than a cursory glance."
I'm never satisfied with either.
Maybe there is a correlation with suburban car culture? First there is the significant correlation between environmental lead during childhood and violence, secondly I think that having a low population density might make people feel more on their own, the highest goal being to protect their family. I'm thinking that people that are used to a high population density, who are in contact with hundreds of other humans a day, get used to this and lower their defenses. Then again I've seen a study suggesting that the violence leves in cities and on the countryside is pretty much the same (at least after lead levels have evened out).
Maybe, hopefully, the decline in violence in the US will continue and it will level out at a similar point as Europe / Asia - then we'll probably know that you were just poisoning yourselves with lead. I hope that this will have some impact on limiting the power of lobbies. Think of how much lead gasoline, lobbied into the world by the oil and car industry, has cost society, if this really was the main cause of the 70ies / 80ies crime outbursts.
The idea that the presence or absence of guns is totally divorced from gunviolence is ridiculous, motive, means and opportunity. Take away the bulk means of easily dispatching fellow human beings in your average culture and you see a decrease in violent deaths. See Australia.
What I'm saying is: I'm skeptical that this alone would bring the aggression levels in the US to European levels (not even speaking about Japan, where it's another order of magnitude below). It would certainly be a good start though and it would be relatively easy to implement. Similar to software development: One should always start optimizing by getting the low hanging fruits.
It's still interesting however, to think about why there is such a cultural difference between the US and Europe, considering our heritage is so close.