A few people have mentioned women being brutalized more well, brutally, as captives than men as a reason why they ought not be put at risk of capture, and therefore limited to support roles. If you read the material amnesty international has online on the subject you can see that while women are far more likely to be the victims of sexual torture men are vastly more likely to recieve what was referred to as common torture (interrogation) and sadistic torture (disfigurement and crippling. So both genders face the possibility of extremely traumatic treatment at the hands of the enemy, and as long as the inherent risks that accompany being taken alive is deemed acceptable (read necessary) for men than it ought to be for women too.