Apparently there are those who do indeed regard "military sci-fi" as a forum for "taking stands." From an obituary of Jim Baen, publisher of Baen Books:
Baen Books offered an antidote to leftism generally in science fiction. It helped rescue science-fiction publishing from the leftist, nihilistic "New Wave" science fiction that had arisen in the 1960s and was concerned, in parallel with postmodernism and deconstructionism in other literature and art, with denigrating Western traditions and values. The "New Wave" was never really popular (New Worlds, the major New Wave magazine in Britain, was bailed out by public money after the buyers and readers stayed away in droves), but it might well have had the purely negative achievement of driving traditional science-fiction writers out of publishing. Baen Books gave -- and still gives -- a voice to stories of traditional Western values like honor, patriotism, chivalry, duty and military valor.
It was probably Jim Baen, more than any other, who rescued the "military science-fiction novel," carrying on into the future and to other worlds the highly honorable tradition associated with the likes of Hornblower and C. S. Forester, and offering a voice against the anti-Western adversary culture so common in modern literature. In its way, and without beating up any obvious political message, Baen Books has played its part in the Culture War, on the right side.
Link provided via Collected Miscellany.