Under what circumstances, if any, could a country plausibility have majority female combat branches of its military? A majority-female military is relatively easy, given how much of the military, any military, is composed of bureaucrats, mechanics, and other support personnel who never see combat or even approach it. Oh, and this is meant to be an ongoing situation, normal, not the result of something like the Nazi-Soviet war in which girls as young as sixteen were armed and expected to fight because it was fight or die. Or worse than die.