Any society that sent its women into combat would have historically died-out.
Because it takes nine months for a woman to bear a child, with half of such children growing to be warriors.
While it only takes one man to impregnate an entire tribe of women.
Therefore any tribe that lacked the genetic, inborn distaste of sending its women into battle, would have died out in a very few generations at most because of the declining birthrate brought about by having fewer mothers.
Meanwhile, those tribes that had genes that influenced a dislike of sending women to war, would have continued to exist.
It drives me crazy to see people trying to rationalize their inborn, genetic, dislike of sending women into combat—you cannot rationalize not sending them. But you can simply understand that it is against human nature and so against the happiness and strength of a society.
Meanwhile I say men should not joint the armed forces in protest.
Let the armed forces be peopled only by women and foolish men who swallow the Kool-Aid about women’s equality.
There's a famous quote that goes something like this.
"Men letting their wives and daughters fight their nation's wars will soon have neither. "