I feel that anyone who would ask such a question is out of touch with modern reality. Women have always served in the military...in the U.S. and most other countries. It is only the role of women in the military that has recently comen under discussion.
Traditionally, women have been excluded from combat roles, and until recently were banned from Naval warships.
Today, women serve side by side with men in support and combat roles. There are now female combat pilots in the Air Force, Marines and Navy. And so far, there have been no problems.
Women in combat have been wounded and captured. Again, there were no problems experienced by the women different from those suffered by the men.
Clearly, women belong in the military. And the nature of their participation need be no different from that of their male counterparts.
Frankly, I would find an all male military somewhat odd and creepy. Why would any social group, corporation or collective endeavor chose to exclude one sex?