I have a feeling this is more about shoring up manpower for big wars than some giant citizenship exercise. The military IS a good route for some people but this would effectively make it a core civic institution.
Probably to increase indoctrination and (I'm assuming for them) 'blind' national loyalty too.
What's funny is when fighting/invading/terrorizing foreign countries...outside of the money we invest into our military tech and training, I assume the main reason the forces are some of the best in the world is because of the self-selecting nature of it. You gotta willingly sign up, then you still might get cut. Characteristically, that's gotta be a different mental make up then say Switzerland, China, or Israel.
Just like you can argue farmers who fight willingly for their country, or join religious extremist groups are gonna be fierce. You could argue self selecting troops are gonna be more disciplined, execute with more composure, etc.
I think another key difference is USA is always in some shyt. Mandatory military service for a country like Switzerland doesn't really effect or challenge the stances of the young people that are being forced to serve.
And the alternative to not serving, paying higher taxes....ain't gonna happen in the U.S. when we're already underwaged with super high costs of living.