Having ubiquitous access to a tool that makes the assaults that will happen more dangerous, increases the fatality of the assaults. Assaults occur at a similar frequency across country borders. So yes the difference between the US and other countries homicide rate is largely explainable by the increased lethality of the tools available. Modern medicine has not saved us from the increased lethality of the tools available. The claimed purpose behind the wide availability of guns in the US, the second amendment, is the claim that it reduces the expected lifespan of tyrants, “necessary to the security of a free state”. Testing this hypothesis is hard and will take multiple centuries of comparison statistics to see if it’s true. However, there is an observed pattern of authoritarians banning guns once they take power, see the following histories (Nazi Germany, Bolshevik Revolution, Maoist China, Cambodia, North Korea, Zimbabwe) Almost no authoritarians allow unrestricted firearms in the populations under their control. ( See also most monarchies of Europe from the past where overlap with guns existed) Guns were carefully kept in the hands of those favorable to the regime. In the US, the constitution forbids The People from having their right to firearm ownership infringed as a hedge to the authoritarian risk. It comes with responsibility of The People to not be flippant about their use and not to abuse that responsibility, but it clearly does happen. But to judge the American approach to guns you have to evaluate it in the context of “Does it actually reduce the lifespan of Tyrants ?” and weigh the goods and bads.