I was one of the last few to go through conscription and service in Germany before it was a abolished I hope it does come back. (including of course the alternative civil service)

For one it instills in young people a sense of duty and direction and also simply physical fitness which many struggle with these days, in Germany an important aspect was always to have civilian supervision in the military ('citizen in uniform') not a sort of separated, private army. A lot of people in the army I talked to have noted that nowadays a lot of people who sign up are just people with limited job prospects. An army of the unemployed is ethically awful. National service should not be pushed on people who do it desperate for a paycheck. Everyone in the country benefits from its defense, so nobody should be able to skip out. I admire the culture of say Israel, Finland, Norway or Switzerland, small countries where this has always been on the mind of people.