The guaranteed next step is to offer the volunteers a long term paid contract at the end of their term. This would probably be well above what they would be paid elsewhere (young men with no university degree, desperate enough to volunteer in the first place).
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.
What could possibly go wrong?
On top of that there is a large dislike in the society against military system. To break that you won't just need "a few years", but likely ~2 generations of compulsory military service for both men and women (e.g. how Isreal does it), that forces a personal connection with the military for everyone.