The Army is loosening up its rules preventing women from being placed in combat arms units. They've been allowed at the brigade level, and now they'll be allowed in at the battalion level. The company and platoon levels are where combat action takes place, mostly, so women won't be directly in Army combat jobs.
But, women have been in combat in Iraq and Afghanistan for years. There is no front line in those wars, so women can find themselves in a sort of combat. As far as I know, though, no women are employed as part of the infantry-style teams that break down doors or take and hold territory. In their limited role, they've done well. Women helicopter pilots do well.
But those roles are not direct combat. Based on my personal experience, I'm against women in combat roles (with one caveat). Here are two examples, both from mixed-gender training. My squad had to ford a freezing cold river. One guy, our strongest swimmer, grabbed a rope, swam across the swift river, and affixed the rope to a tree. The other end was likewise tied to a tree. The rest of us, in our combat gear (and taking the swimmer's), then pulled ourselves hand over hand across the river with the rope.
Ever done that? Well, the river pulls at you, and you're mostly underwater, cause the rope stretches and you're packing a lot of weight. So you're in that icy water, trying to stay above water, and trying to get across. To keep from bogging down, we left at intervals, one a minute or something. Well, the female in our squad was really struggling. She didn't have the upper body strength to pull herself across very quickly. So she went slowly. Unfortunately, she was in the middle of the pack.
Understandably, the guys behind her quickly caught up (you can't really see ahead very well, until you run into the person in front of you, plus you're hurrying because it fricking freezing). So before long we had 2 then 3 people at the same point on the rope, increasing the drag and stretch, and going slowly. I was one of those guys stuck behind the gal. I thought I wouldn't make it, and since I'm a poor swimmer, that would have been the end of me.
Another example. We dropped into a "hot" landing zone (again, training). One of the females had been assigned to carry the radio, and as I recall, she had volunteered for that duty. Well, back then (the 80s) that backpack radio (PRC-77) was heavy. So, we jumped out of the helicopter and took off running to get out of the fire zone. The radio gal didn't make it; the radio and her gear was just too heavy. She collapsed before even 100 yards. Two guys had to run back, one to take over the radio, one to help pack her out of harms way. Again, just not enough strength to perform combat duty
Now the caveat. The females seemed to have sufficient heart and courage, just insufficient strength. In case you're not familiar with the Army Physical Fitness Test, it has substantially easier standards for women. Example; a minimum running time for a man is the max score for a women. For 22 years olds, men have to do 40 pushups to get a passing score, women have to do 17. Women get the max points for 46 pushups, men need to do 75 to get the max.
So, if the Army uses the exact same physical standards for both men and women, then women who pass that test should be allowed into combat units.