Although shootings and the like are not a problem in the UK, when I went back into education this year at a “further education college” (which differs from college as it’s meant in the US - this is an institution that provides education for those aged 16+, so includes both minors and adults), we nevertheless had occasional drills for what to do in the event of a shooting or other attack. I think it’s not as comprehensive as the preparations students in American schools need to make, but it was still something the college prepared for with the same regularity as the potential for evacuation during a fire.
So even in non-US developed nations, the potential for this kind of violence is acknowledged as a risk.