I like the way the South Koreans did it...two years national service (for males) in either the military or police. Educational deferrals can be obtained, but the two years eventually comes due (IIRC it was at age 26 or 28 or some such). Many of the hockey helmeted riot police you see in the news clips from South Korea are actually conscripts under the direction of professional police NCOs and officers...for many of them, getting spit on and worse by the radicals in society gives them little sympathy for such elements after they leave the police service.
To diagree is one thing. To protest is one thing. To show contempt with complete disrespect is another.