Combat doesn't mean merely firing a gun; of course women can do that. Combat doesn't mean merely getting wounded and dying; of course women can do that. Combat means aggressively seeking out and killing the enemy. A lot of people have a very sanitized view of what battlefield fighting is all about. They seem to think it means a quick gun fight and then returning to the base with separate shower and toilet facilities and a ready mess hall.
Retired Army Major General Robert Scales explained in the Washington Post that we know from experience with war that the intimate, deliberate, brutal killing of our country's enemies is best done by small teams of men. Four solid buddy pairings of men led by a sergeant compose a nine-man battle-ready combat squad. These squads are bound together by the "band of brothers" effect, a phrase borrowed from Shakespeare's Henry V. Centuries of battlefield experience have taught us that this brotherhood is what causes a young man to risk and even sacrifice his life willingly so his buddies can survive, and that cohesion is a male-only relationship that would be irreparably compromised by including women in the squad.
Listen to the radio commentary here: