> Run the scheme for a few years, and you will have a large number of, young, high-school-level educated people that are financially dependent on the army. Thus, a militarized society
Finland, Sweden, Norway, Switzerland, Austria, Brazil, Chile, Mexico and Thailand each have active conscription [1]. The slippery slop you describe is far from inevitable.
You probably have no idea what you're talking about. Mandatory conscription (which I have personally served) is for a fixed term, so your livelihood is not tied to the army paying your salary. It's more of a semi-unpleasant mandatory intermission in your life plans.
Also, if you have decades of mandatory conscription then there is no slope to slip. Germany on the other hand is now on a slope, since they regress from a fully professional army back to conscription. How much down they will slip, remains to be seen.