I honestly think that forcing everybody to join the military for a year, regardless of their interests, education and physical condition, is a waste of time. By 18, I had zero desire to join the army, a terrible physical condition I had mantained throughout all my teen ages and enough grades to sign up at any university I wished to. Being forced to join the army would have meant a wasted year in my life which I did use for far better things (signing up for two degrees)- and I know many people who were still forced to do so until 2002 (Spain) and who didn't really care about it in the slightest. I think it should be encouraged for people who are without a direction and might be interested in this sort of career, but in no way forced, and much less for everybody.
There are people who are good for some things and people who are good at some others. This makes as much sense as forcing everybody to spend one year at a plot of land in some random town in the country cultivating food or taking care of cattle. Yeah, it's a necessary job to keep the country running, and it does teach you the value of sweat and effort, but... is it necessary for everybody to learn to do it at this point in time? The wonders of technology mean that you can keep an extremely efficient and deadly military running with less people than ever before and produce enough food with minimal labour. In turn, you get lots of people free to do other things that are also important for society. And I'm glad we have moved from a Modern-Age vision of society to a more Contemporary one.