> What if it didn't delay your education? In some countries an undergrad degree is only three years. I'd take a person with 1 year of civil service + 3 years of a degree over someone with 4 years of a degree any day.

In a world where 1 year of civil service was normal for most people, I'm skeptical that this is the choice the labor market would consistently make. Remember, if pretty much everyone in society is doing the same national service, then that means the military had to find jobs for everyone to do, including people with mediocre general competence or who are in fact bad at following written instructions in English. "I completed my mandatory national service, just like pretty much everyone else" is not that strong of a signal.

In the Soviet Union, smart math and science students often competed hard for academic and technical positions that would let them fulfill their military obligation by doing some kind of math or science for the Soviet state, instead of being a conscript foot-soldier for a few years like was normal for Soviet males (boot camp sucks for everyone, but it really sucks for most smart nerds). If the US had a system like this, there would definitely be industries where it was normal for everyone working in them to have avoided the worst of actual combat training somehow or another - or for actually having done normal soldiering to be a culturally-unusual thing to do. Just like how in our actual society it's unusual for someone who works at a silicon valley tech company to have actually volunteered to serve in the US military earlier in life.