I have a husband who's ex-forces (Navy) and sounds like your DH, MB. So I'm predisposed to like the idea. Having said that, I do think it only suits some personalities and for others, it can be a total nightmare, or turn them into raving bullies, so my response would probably depend on what sort of person I thought DS was.
Don't forget, pfer, that as well as being sent to die for your country by gits of politicians, people in the armed forces are also in the front line of civilian crises like getting aid to Tsunami victims, or peacekeeping duties in volatile parts of the world. Meaning there is a lot of work they, and their families, can be proud of.
But really, you know, by the time DS is old enough to contemplate it, it will be none of my business, frankly. I'd probably be proud and frightened in equal measure, and I'd certainly ask him what he'd do if he was asked to fight in a war he didn't agree with, but in the end I'd have to put up and shut up, I think.