Ta Steven, I thought you didn't just mean military but when i googled all I got was military! I wouldn't have liked to be forced into military service, not gonnna happen now but I feel for those younger. Some got out of it in the past, others were forced; bad scene, imagine if they had to go into a war in which they didn't believe & ended up killed?
As for non-military NS which some countries did in the past, who wants everything mapped out from age 18? Not fair, some would be suitable& embrace it (think back to school days) but not others. Lots of youngsters at 18 are extremely young & need a bit of protection while others are more mature. How can one generalise?
I agree with you about routinely arming the cops.