Also, nations that are islands have a much easier time eliminating guns from their borders, once the populace agrees that they should be.
The sad part is that the U.S. has a huge population of people that still don’t think anyone else’s rights to the pursuit of happiness and peace take precedence over their constitutional right to own guns, and if Sandy Hook didn’t move the needle then I don’t see what will.
But even if they agreed to take that action my first two points pose a pretty impossible logistical task to actually remove guns from our society