Listen to Gumby. I think you guys who are despairing of the military's "social experimentation" and "PC-ness" are missing the historical perspective.
The military has been a crucible for social change, not a laboratory, all the way back to the Revolutionary War. Minorities were in ranks with the colonials, and felt entitled to the same rights as new American citizens-- even if they were Irish or Scots. (Remember the book
"How the Irish Became White"?) During the Civil War, the military of both sides offered considerable incentives to African-Americans to "integrate" them into the fighting. When racial minorities were sent overseas in WWI and WWII it became quite clear to them that they were treated far better in Europe & Asia than in the South and the rest of America. A huge African-American migration resulted in WWII from the South to North-central America, especially Chicago & Detroit, as part of labor the war machine.
If PC had been a word in 1948 then Truman would have been accused of being so. Women broke the military's glass ceiling far sooner, and in proportionally greater numbers, than on Wall Street or in much of industry.
Look at how the military accelerates citizenship approval for its immigrant servicemembers. If you're an American fighter then it's probably appropriate to have a piece of paper proclaiming that you're an American citizen.
Of course not all parts of the military are joyously leading the charge to social integration. I once listened to a SECNAV describe the submarine force as "a bunch of dinosaurs-- the last bastion of male WASP Republicans who would soon be extinct if they didn't change their ways". I listened to submarine admirals explain with sincere & earnest expressions why women couldn't be exposed to ionizing radiation from submarine nuclear reactors (despite the women doing so on aircraft carriers) or be at sea on submarines due to the emergency MEDEVAC risk of an ectopic pregnancy (despite my having just arranged a submariner's MEDEVAC for a ruptured appendix with even less warning).
My spouse and I have served with a number of homosexuals (that we knew of) and possibly many more. No one gives a damn what turns you on as long as you're willing to kill people, break things, and (oh, yeah) support a watchbill. I'm delighted that women are joining the submarine force (especially if my daughter chooses to do so) while acknowledging that I would have not wanted to compete for promotion against someone who's more motivated and more qualified. Especially my spouse, who's also smarter.
In the military the urban legends HAVE to be researched & debunked. Racial genetics has not been proven to affect on-the-job performance. Sexual preference doesn't appear to affect it either, despite the homophobic concerns of a minority of (professed) heterosexuals in combat units. There are significant gender differences, and whaddyaknow it turns out that women tend to have faster reflexes and make better judgments than their male counterparts. Not all women, and not all men, but enough to make a statistically-significant difference.
About the only male military advantage is the fact that testosterone speeds muscle repair and injury recovery. Having said that, both genders have a bell curve of testosterone levels-- my nephew the Army Ranger tells me that it's been shown some women can still kick the asses of male Rangers in performance, stamina, and endurance.
As for fighting the barbarians, it's been proven many times that diplomacy is cheaper than warfare. There are many alternatives to actual combat, but once you start fighting you can't go looking for "offramps". As much as I may have difficulty perceiving the necessity of all forms of Pax Americana imperialism, I'd much rather do it "over there" than "over here".
Those of you who think the military has been hampered since Vietnam have clearly never experienced the transition from conscription to volunteer forces. Even in 1979 we were dealing with the overhang of the Vietnam "hollow force", and its drug culture persisted well into the 1980s. I don't know any military servicemembers or veterans with a few gray hairs who would want to go back to the "good ol' days"...