I would generally say that whenever there's a war going on (or looks like there's about to be a war going on) it's a pretty terrible idea...but then, I'm just not too fond of the idea of getting myself killed over somebody else's squabble.
Generally, if you have a college degree or other higher education though, I think that makes it very easy to enlist as/become an officer, and my understanding is that officers get better pay, more perks, and are less likely to be exposed to extremely dangerous conditions than non-officers, so if he's really passionate about the army, it is good that at least he waited until after completing college.