Katherine Miller got pretty good at hiding her sexuality in high school, brushing off questions about her weekend plans and referring to her girlfriend, Kristin, as "Kris."

She figured she could pull it off at the U.S. Military Academy at West Point, too. After all, "don't ask, don't tell" sounded a lot like how she had gotten through her teen years.

But something changed when she arrived at West Point two years ago. She felt the sting of guilt with every lie that violated the academy's honor code. Then, near the end of her first year, she found herself in a classroom discussion about gays in the military, listening to friends say gays disgusted them.

"I couldn't work up the courage to foster an argument against what they were saying for fear of being targeted as a gay myself," Miller told The Associated Press in an interview this week. "I had to be silent. That's not what I wanted to become."

What she has become is an unlikely activist for repealing the ban on gays serving openly in the military. She resigned from the academy in August and within days was one of the most prominent faces of the debate. Yet her greatest hope now is that she can return to the place she just left.

For that to happen, President Barack Obama must make good on his promise to gay rights groups that he would push to repeal the 1993 law by the end of the year. The U.S. House already has signed off on the idea, and the Senate is preparing to debate it in the coming weeks.

The Defense Department on Tuesday will release a report that will help shape what Congress decides. The study has examined whether lifting the ban can be done without disrupting the armed services and current war efforts and includes a survey of about 400,000 troops.

Defense Secretary Robert Gates and the chairman of the Joint Chiefs of Staff both have said they would rather see Congress change the law than have it struck down by the courts and risk losing control of how the changes would be put in place.

Adm. Mike Mullen told ABC's "This Week" this month that asking people to lie about themselves goes against the integrity of the armed forces.

Miller, 21, grew up in rural northwest Ohio, where she was captain of her high school softball team and voted most likely to become president.

She started dreaming of going to West Point around the time she turned 16 — more than a year before she came to accept that she was gay. Even after that, the "don't ask, don't tell" policy was no more than a passing concern.

She wanted to be a leader at the academy, someone with honor. She excelled, ranking near the top of her class of more than 1,100 cadets going into their third year. But Miller also was hiding in fear. "I realized that I wasn't becoming the leader of character that I wanted to be," she said.

Other gay cadets in her small circle of friends tried to persuade her to stick it out. Conforming, after all, is a tenet taught in the military.

"It was definitely an option," Miller said. "I just chose not to live my life that way. I'm pretty stubborn in my values. I needed to get out and declare who I was."

She still wonders whether she should have stayed and tried to survive under the policy. "At the same time, I don't think that I would've made nearly the impact that coming out publicly made," she said.

What hurt the most after her resignation were negative comments from people in her hometown. Some were hateful. Some accused her of wasting the military's time and money. Some called her selfish for taking a spot in the academy from someone else.

"My intentions were honorable. It wasn't to become a gay rights activist," she said. "It was something I was forced to think about once I got there."

Miller resigned a week before she would have been required to commit to finish her final two years and serve five years in the military. Cadets who withdraw in their first two years don't owe the government service or compensation for the education and benefits they've received.

There was no answer Friday at the academy's public affairs office. A West Point spokesman said in August that Miller had done very well academically, militarily and physically while at the academy.

The harshest criticism from her former classmates came after she wore her dress whites while walking the red carpet with Lady Gaga at the MTV Video Music Awards. They felt she was using her uniform to make a political statement.

Miller doesn't regret the decision. But she doubts she'll wear her uniform again — at least not until she's back at the academy.

"I'm trying to get back into the military," she said. "I'm not trying to make that difficult when that occurs."

She calls strangers "sir" and "ma'am." She wears her black hair tightly pulled back.

Miller is now preparing her application to the academy in case Congress acts quickly on "don't ask, don't tell." She knows not everyone will welcome her back but thinks the military will become a stronger institution for it by opening up to all qualified candidates.

"There's going to be hostility toward me, and that's inevitable," she said.

For now, Miller is attending Yale University and taking three classes, including U.S. lesbian and gay history and sexual gender in society — courses not found at the academy.

She has found freedom in the school's gay community and likes staying up late. Still, her heart is in West Point.

She misses the respect, the hierarchy — everything but one rule.