the reason scandanavian countries adopt mandatory military participation is that they rely upon their citizens as reservists. the active military is very small for these countries, and if shit were to hit the fan, discharged citizens who previously received training are called to arms.
the us and canada adopt a completely different model, relying upon large numbers of active troops. if either country relied upon mandatory periods of enlistment they wouldn't have the resources to accommodate the influx. it's apples and oranges.
forgive my directness, but it's pretty stupid to say that military service "straightens people out." a career in the military doesn't equate to being a stand up citizen, and the problems of people in the recruitment age range would have been better fixed with improved education and family structure rather than someone barking at them while they do pushups.
good luck, fred.