In English, there is no collective generic noun *at present* to match the French "militaire". The American singular usage of "troop" is a good example of how some English speakers are still struggling to find one, and I imagine that a word will emerge to do the job sometime before I die.

Or maybe not. English is weird in many ways, and this is one.

(BTW, "soldat" is not generic in most of the Francosphere; it is the ground-pounding counterpart of "matelot". The accepted generic in French Canada is "militaire".)

In Canada, where the armed services have been a singular since 1968, the adjective "military" is approaching the status of collective noun for the services themselves, as in "the military is the biggest source of government spending", or, "he's in the military so he's never home". But we have no accepted generic noun for individual persons. "Serviceman" was the word in 1950, but that doesn't work any more with so many women in the ranks.

I don't like "in the military", but I'm an Olde Pharte and an editor at that. At least it's better than using "soldier" for everybody who wears the National Tweed.