The Israelis tried putting women in combat back in the 1960s and it didn't work. Men are biologically programmed to be protective of women. If you don't think that, then tell me what you'd think of the following situation:
A man and a woman are at home sleeping in bed. A thug starts trying to break in. So the man grabs the children and hides in the closet, leaving his woman to go handle the thug. Now imagine the man trying to explain that to a television news person interviewing them on what happened. People would wonder what on Earth was wrong with that man. It doesn't matter how brave the woman is, that's just the reality of it. And I don't care what anybody says, an injured women crying out in pain has a mental affect on a man different than the same happening to a fellow man.
The other problems with women in combat are simply physical. Women do not have the physical strength for being a combat soldier. There is a large, significant, strength and size differential between men and women.
We have separate men's and women's sports teams. Try making women play on men's hockey teams and soccer teams and so forth. You'd wipe all women out of the sports.
We have separate physical fitness standards for male and female police.
We have separate physical fitness standards for male and female firefighters.
We have separate physical fitness standards for men and women in the military. Why? Because if you made women adhere to the same standards as the men, you'd disqualify a massive number of women from military service.
I am 5'10, 144 lbs, which is pretty thin by man standards and not tall. Maybe slightly above-average in terms of height. Now despite that, I am still stronger than 95% of the women out there. The only women who would be stronger than me are serious athletes who do a lot of strength training. 5'10, 144 lbs is nothing special for a man, but a 5'10, 144 lb woman is pretty big for a woman. That's a real long, tall Sally, if you will. Most women are shorter than 5'10 and if fit, around 100 - 130 lbs.
This creates some major problems when you're talking a job like infantry, where the standard combat load for an 82nd Airborne Division infantryman in Iraq was 130 lbs. Carrying all that weight does hell on a man's body, let alone a woman's:
http://www.vva1036.org/_/rsrc/1309111959257/pictures/soldier%20kneeling.jpg?height=304&width=400
And that's just standard infantry. To be in something like Special Operations (SEALs, Rangers, Special Forces, etc...), the requirements for marching distance and so forth are much higher.
Now one could say that they should only let women in who could meet the standard, but that wouldn't happen. You'd have so many women fail, that sexism would be cried, and they'd have to push a certain number through. They do this already at Airborne School, which is one of the easiest schools in the military. There's a one pullup requirement. If you can't accomplish one pullup, you're supposed to be disqualified. Do they disqualify all the girls who can't do one pullup though? NOPE, because they'd fail most of them then. It only really applies if you're a guy. To join the Marine Corps, men have to be able to do pullups. The Marine Corps PFT (Physical Fitness Test) is pullups, situps, and a three-mile run. But what is the upper-body test for a woman? A flexed-arm hang. Why? Because requiring girls to do pullups in order to join the Marine Corps would disqualify a whole lot of them. In the Army, the PFT is pushups, situps, and a two-mile run. For the 18-24 year-old men, the minimum number of pushups to pass is 40 in two minutes. What is it for the women? Managing 40 pushups in two minutes is maxing the pushups portion of the PT test for a female.
And even then, the PFTs are misleading. A woman might be capable of acing the men's PFTs for both the Army and Marine Corps, but that just means she can do lots of calisthenics and running. Load her up with a heavy amount of gear, turning her into a pack mule, and then see how far she can march. The PFTs don't really reflect the fitness needed for a combat soldier, they're just physical fitness tests created to have a base standard of PT in the military branches.
Then there's the hygiene issue. Having a vagina creates some serious hygiene problems for women if they are unable to keep that area clean constantly, an issue that men do not have. I think bravery and intelligence-wise, women are equal to men and can do things like fly helicopters and fighter planes just the same, but combat, that is trying to deny millions of years of evolution in terms of programmed behavior and physical capability.