After 17 years, "don't ask, don't tell" may finally be on its way out. Even if the Senate resists the latest efforts to end the policy, it appears that most members of the military - from the chairman of the Joint Chiefs of Staff on down - support the law's repeal.

But there's one part of the military where resistance is greater than in any other: the United States Marine Corps.

That is clear from early reports about a survey sent to 400,000 active duty and reserve service members on "don't ask, don't tell" that will be officially released next month. More than 70 percent of respondents, spanning all branches of the military, said the effect of repealing the prohibition on openly gay troops would be positive, mixed or nonexistent. But about 40 percent of the Marine Corps respondents expressed concern about lifting the ban.

Top Corps leaders, past and present, haven't been shy about stating their concerns. While serving as chairman of the Joint Chiefs of Staff, Marine Gen. Peter Pace said in 2007 that "homosexual acts between individuals are immoral and . . . we should not condone immoral acts." (He later clarified that the comment reflected his personal religious views.) While serving as Marine Corps commandant, Gen. James Conway told reporters in August that "an overwhelming majority [of Marines] would like not to be roomed with a person that is openly homosexual." Most recently, the current commandant, Gen. James Amos, while expressing support for the survey, echoed Conway's comments, eliciting a mild rebuke from the chairman of the Joint Chiefs, Adm. Mike Mullen.

What is it about the Marines? Compared with the other services, why do a disproportionate number of them overtly resist ending "don't ask, don't tell"?

I have studied, taught and interviewed Marines for 15 years and have gained great appreciation for the history and culture of the Corps, so much so, in fact, that I began teaching at the Marine Corps War College in Quantico almost three years ago.

Marines have survived and thrived as a service in part because they exemplify everything warrior. (I have never seen as many trucks with gun racks as I do driving on the Quantico base.) They pride themselves on being the toughest service, serving in the most austere environments under the most demanding circumstances. This pride has been forged throughout history, from Iwo Jima to Khe Sanh, from Fallujah to Helmand province.

In the Corps, the creed that "every Marine is a rifleman" means that no matter the Marine's specialty, he or she is ready to fight. Marines do battle where the stakes are high and the quarters close. Although they have individual specialties, they all have infantry in their blood.

As a rule, ground pounders are more conservative, resistant to change and likely to uphold tradition. This equates to a fear of the unknown - in this case, serving in combat with an openly gay Marine.

Every Marine sees himself or herself as on the front lines, if not at the moment, then ready to deploy at any time. The Marine Corps is a smaller service than the other branches, with a greater singularity of purpose. That attitude is part of Marine Corps exceptionalism broadly, as well as when it comes to the repeal of "don't ask, don't tell." Anything that could dilute the warrior ethos will face a challenge.

I am an openly gay woman, equally comfortable at Quantico and in Dupont Circle. Each of these worlds holds negative stereotypes about the other, and like all stereotypes, they tend to break down on an individual level. Yet for some in both cultures, the notion of a gay Marine seems almost impossible, as though this most masculine and punishing service simply isn't for gay people.

You don't need to spend time with Marines, as I have, to realize how important the warrior ethos is to them. Simply turn on the television and see how the Corps markets itself: Do you have what it takes to join the few, the proud? When discussing their high retention numbers with the Marine Corps leadership a few years ago, I was told that the Corps prides itself on not having to pay big bonuses, as the other branches do, to keep people in the force - the honor of being a Marine is all the reward offered or desired. It's part of why there are no former Marines, only retired Marines. Once you've joined the tribe, unless you do something that goes against the Corps' values of honor, courage and commitment, you never leave.

In the Marines, anything that seems to contradict or challenge that warrior culture is treated like a foreign particle entering a body's immune system - it is rejected. This visceral reaction will not change if we dismiss those who value these traditions.

But the Marine Corps culture itself, I believe, will eventually lead the service to support the repeal of "don't ask, don't tell."

Although I am not closeted, the fact that I am gay does not come up in my job as a professor at the War College. Nor should it. I am not a Marine. I have not been in combat with Marines. The students at the college are the future leaders of the Corps, and I lead respectful debates in class on issues from grand strategy to counterinsurgency operations. I'm sure that my sexuality does not fit with the private views of every Marine. But it doesn't have to. I was hired by the college as a professional and honored as the 2010 outstanding Marine Corps University civilian professor. In my experience with the Marines, professionalism trumps sexuality.

I am very sympathetic to the strain that the Marine Corps is under and would never support a policy change that I thought would hurt the Corps in a time of war. I have researched the implications of repealing the law, willing to land wherever the facts led me. The argument that we can't repeal the policy because it would impair troops on the ground from carrying out their missions is specious; the opposition to the policy on practical or logistical grounds is surmountable.

The values of honor, courage and commitment are inseparable from the Marines. By definition, gay and lesbian Marines break one or more of these core tenets every time they have to hide or lie about who they are. Eventually, gay Marines must out themselves by upholding Corps values, or continue compromising the very values that make them Marines.

Repealing "don't ask, don't tell" would not mean that hundreds of gay and lesbian Marines would immediately come out of the closet. But it would mean that they could keep their personal and professional integrity. The examples from other countries where homosexuals are allowed to serve suggest that many will go about their lives as normal, but without the fear of being discharged if discovered.

The key to reconciling Marine culture with the open service of gay men and women will not be found among the rank and file or even among closeted service members; it must come from Corps leaders. Most research on how to integrate minority groups into the military has a common thread: the utmost importance of leadership to the process. The fact that the current and prior Marine commandants have expressed discomfort at the prospect of the demise of "don't ask, don't tell" is unfortunate because the generals risk creating a self-fulfilling prophecy, hurting the Corps they desire to protect.

"Don't ask, don't tell" will be reversed in time. And as the military survey indicates, a majority of the Corps does not see a risk in the repeal. How the change affects the Marines is up to the leadership. A Marine officer once told me that, besides all Marines being riflemen and riflewomen, what sets them apart is discipline: "If the law changes," he said, "we will comply with the law. You can take that to the bank."

I believe he's right. The United States Marine Corps is the most professional force in the world. There is no reason to think that it will be less adept at integrating gays than Britain, Canada or Australia (just three of the 26 countries that allow gays and lesbians to serve openly, according to the Servicemembers Legal Defense Network).

The current leadership should look to a fellow Marine for guidance. Staff Sgt. Eric Alva stepped on a landmine and lost his right leg only three hours into ground operations in Iraq in 2003; he was the first service member to be wounded there. He also happens to be gay. Alva received a medical discharge and has gone on to work for the repeal of "don't ask, don't tell." At an event in 2007, he came out publicly, saying, "I'm an American who fought for his country and for the protection and the rights and freedoms of all American citizens - not just some of them, but all of them."

The Marine Corps leadership should not only accept such sacrifices but honor those who make them. The Corps' motto, "semper fidelis," means "always faithful." There is no qualifier for sexual orientation. Once a Marine, always a Marine.

Tammy S. Schultz is director of national security and joint warfare at the U.S. Marine Corps War College. The views expressed here are her own and do not necessarily reflect those of the Marine Corps University. She will be online Monday, Nov. 22, at 11 a.m. ET to chat. Submit your questions before or during the discussion.