Some clarification might be helpful:
1. Men typically tend to be larger, more muscular, and more aggressive than women. I believe we are both agreed on this point.
2. Combat in general involves the above factors. However, combat also rewards other separate factors such as training, available equipment, and surrounding conditions. These other factors are generally not reliant upon gender-specific traits.
3. Therefore, if the combat situation is heavily dependent only
on strength, size, and aggression, then a male will typically be more suitable for the situation than a female. (I say "typically" because there are outliers for each gender, ranging from small weak men to large strong women.)
4. Conversely, in a combat situation where other factors (training, equipment, and surroundings) are important and size, strength, and aggression are not important, a typical male will not be any more or less suitable than a female.
The question is: how often do you expect to see 3. (a situation where the male traits are a benefit) and how often do you expect to see 4. (a situation where the male traits are not). I think our main difference of opinion is here - a disagreement of how frequently one or the other crops up in conflict situations.
If you expect to see 3. most frequently, then women in the military would be a rarity. Before the advent of gunpowder this was almost always the case - even iconic female soldiers like Joan of Arc tended to act in leadership roles rather than arm-against-arm fighting roles. After gunpowder, poor-bloody-infantry roles still require the use of the muscular advantages you list, and many modern armies still exclude females from regular infantry for that reason.
If you expect to see 4. most frequently, then women in the military would be common. Although body strength is still usefully applied to many situations (such as the logistics and heavy weapons handling you describe), the absolute lower boundary is significantly more elastic. Outside of the poor-bloody-infantry, with less emphasis on hauling packs or hefting a blade, the muscular disadvantage of a female is less pronounced. Mission profiles that involve machinery, special equipment, specialized training, and so forth will generally go to whoever shows a special aptitude for them regardless of gender. Some specific mission profiles actually favor female physiology - women are less likely to black out at high-g aerial maneuvers than men are, because of shorter blood vessels in the neck.
External political or manpower issues may also factor in - most integrated armies also have social policies that encourage gender equality. In the cases of Russia and Eritrea, manpower shortages also likely placed a higher value on any
soldier who was willing and able to fight, regardless of gender. Depending on mission profile, the fact that a female soldier can carry less equipment weight of her male counterpart may be far less important than the fact that she's willing and able to put themselves in harm's way to attack the enemy, during a time when most citizens are not. (Female snipers being a key example of this.)
One other argument against
inclusion of women in the military, which has now largely fallen out of favor, was that a female's effect on morale would be negative. In part this was from concerns over sexual relations between soldiers and all the attendant complications and distractions, but lately this has largely been subsumed into a matter of general troop discipline rather than any issue peculiar to gender alone. (The exact same dynamic was at work with the US Army's ban against homosexual soldiers, which has now been overturned.)
The only other morale argument I've heard was that male troops suffer a greater morale hit when they witness a female colleague's death or injury in combat than when they witness a male colleague's death or injury. As this seems to be more of a psychology issue, I am unaware of the armed forces issuing any specific finding on its validity. Presumably the US Army's policies of gender integration indicate that it is not particularly persuasive.
There is one point you make that I'll refute specifically though:
NAto wrote:Physically however there is just no comparison. I've got enough experience in martial arts (weapons included) to know that the average woman stands no chance against the average man.
That has not been my experience. I trained in the military for a year*, and I studied martial arts** as a civilian for two decades. The closest I could come to your statement might be "the average male combatant typically enjoys an advantage in striking strength and reach", which is nothing even close to saying "the female stands no chance". My legal experience bears this out too: a significant portion of the criminal cases I reviewed involve a female defendant and a dead male after a physical confrontation that went wrong - and in many of the cases, the woman wasn't even specifically trying to kill the male but was acting out of self-defense.
* UK Royal Air Force, 1994-95.
** Shaolin changquan, shotokan karate, judo, aikido, sanshou, mantis changquan, krav maga.
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