The Pentagon's just-released survey confirms that nearly 70 percent of troops say they have already served in a unit with gay or lesbian members and that it made little difference. Combat veterans have said for years that when the bullets are flying, the only things they care about are whether warriors can hit their marks, think on their feet, follow orders and be willing to sacrifice themselves to save their comrades. That's it. What troops do in their off hours is their affair.

Indeed, the notion that troops who walk willingly into a wall of bullets are afraid of a few gay people in their ranks has always been a little absurd. Still, fears about gays in uniform are real - because they go to the heart of warrior culture and of masculinity.

Young men and women join the military for numerous reasons, the Pentagon's many surveys show. First and second are, respectively, getting the military to pay for college and acquiring skills valued in the civilian workforce. Next come the larger motivations, such as patriotism, self-sacrifice and being part of a cause greater than themselves.

But another reason that male troops sign up and that they talk about in their more reflective moments is to prove their masculinity. This has been true since hunter-gatherer days, when a warrior facing death was the ultimate proof of courage and, yes, maleness. Joining the military is a rite of passage and a sign of maturation. Serving in uniform signifies the transition from adolescent boy into the brotherhood of adult men.

Straight soldiers and Marines who have a few years under their belts, and have done a combat tour or two, will more readily talk about this. They often say they enlisted in part because they wanted to prove to someone - maybe a father, their family or a sweetheart, but most often to themselves - that they were brave men willing to suffer the consequences of their adult decisions, even if that included death. That is one of the essences of masculinity, they have said in interviews.

But the scores of gay servicemen I have interviewed over the years express an identical desire to prove their strength, courage and masculinity. It isn't about proving sexual prowess, both straight and gay troops say, but about adulthood and, ultimately, male virtue.

It is notable, too, that many gay troops have said that at age 18 they were still unsure of their sexuality and figured that going into the military would make them straight.

It didn't. When asked if being around all those young men - the temptation, the proximity - made them gay, not one said yes.

Homosexuals say that the crucible of basic training, the hardships of military life and the stress of combat allowed them to discover, understand and accept who exactly they were. War is an ugly business. It forces people to look deep within to find reserves of strength they didn't know they had. They quickly begin to see themselves, and the world, squarely for who and what they are.

For the vast majority of homosexuals in the services, military life gave them the courage to acknowledge that yes, I am brave, I am masculine and I am also gay. They, too, live every day knowing an enemy's bullet can abruptly end their lives. But they live with the added fear that at any moment a fellow soldier could rat them out for their sexual orientation and end their military career. These are not cowards.

Meanwhile, for straight servicemen, the fear of gays is much like that expressed when females began entering most U.S. military units in the 1990s. Men suddenly saw that women could fly fighter jets, sail ships, fire cannons and face death, and some felt it diminished the band of brothers they joined to prove that they were, well, men. Similarly, if gay men can also make war, many have to wonder if that makes them less masculine.

It doesn't, and it shouldn't, but some young men will feel that way. And that's when the Pentagon's core competence - rigorous training - comes in. The military went through some conniptions in the 1990s establishing institutions and equal opportunity programs to train troops on the integration of women. At times there was visceral resistance to women entering combat roles - recall the 1991 Tailhook scandal. But the training worked, and women have been fully integrated into the U.S. military except for direct ground combat.

It took nearly 30 years to fully integrate African Americans into the armed forces, and it's going on 20 years now for women. It will likewise take a few years for gays to be fully accepted. In the end, however, the training will work, acceptance will grow and homosexuals will be regarded by their peers as equally brave and valuable warriors.

The writer is a contributing editor at National Journal. He previously reported on the military for Army Times.