They are images that Americans had never seen before. Jubilant young men and women in military uniforms marching beneath a rainbow flag in a gay-pride parade. Soldiers and sailors returning from deployment and, in time-honored tradition, embracing their beloved — this time with same-sex kisses.

It’s been a year since the policy known as “don’t ask, don’t tell” was repealed, enabling gay men and lesbians in the military to serve openly, no longer forced to lie and keep their personal lives under wraps.

The Pentagon says repeal has gone smoothly, with no adverse effect on morale, recruitment or readiness. President Obama cites it as a signature achievement of his first term, and his Republican challenger, Mitt Romney, says he would not push to reverse the change if elected.

Some critics say the repeal has infringed on service members whose religious faiths condemn homosexuality. Instances of anti-gay harassment have not ended. And activists are frustrated that gay and lesbian service members’ families do not yet enjoy the benefits and services extended to other military families.

Yet the clear consensus is that the repeal has produced far more joy and relief than dismay and indignation. There is vivid evidence in photographs that have rocketed across cyberspace, such as the military contingent marching in San Diego’s gay-pride parade and Marine Sgt. Brandon Morgan leaping into the arms of his boyfriend after returning from six months in Afghanistan.

Tens of thousands of people clicked the “like” button for the photo on Facebook, and Morgan acknowledged it was “a great moment in history.”

“But when it comes down to it, we didn’t intend for this go to worldwide,” he said. “We were just happy to be together.”

There have been many such milestones since the repeal took effect Sept. 20, 2011:

●In December, a lesbian sailor won the right to the coveted “first kiss” when the USS Oak Hill returned to port in Virginia after 80 days at sea. The crowd on hand to welcome the ship screamed in delight and waved flags as Petty Officer 2nd Class Marissa Gaeta shared a kiss with her partner, Citlalic Snell — a moment captured in a YouTube clip that drew 1.5 million viewers.

●In June, Air Force Tech. Sgt. Erwynn Umali and his civilian partner were united in a civil-union ceremony at the chapel at Joint Base McGuire-Dix-Lakehurst in New Jersey, with a Navy chaplain presiding.

●In August, longtime Army officer Tammy Smith became the military’s first openly gay general. Her wife, Tracey Hepner, did the honors of pinning on the general’s star during the promotion ceremony.

Smith and Hepner were married in March in the District of Columbia, one of many same-sex couples inspired to wed when they no longer had to conceal relationships. Among other newlyweds are Air Force Major Adrianna Vorderbruggen and her civilian wife, Heather Lamb, who married in June, and are raising a 17-month-old son near Washington.

Lamb said she attended a squadron family and spouse support event, and was recognized by the commander during Vorderbruggen’s recent promotion ceremony.

“None of it could have happened before repeal,” Lamb said.

Another couple, Alisdair Mackay and Stephen Peters, were married last December in New York shortly before Mackay, a Marine Corps major, began a one-year deployment to Afghanistan. Peters, a former Marine discharged under “don’t ask, don’t tell” in 2007, said the post-repeal experience had been wonderful, by and large, for him and Mackay.

“The Marines he works with are completely supportive,” Peters said. “He’s able to be honest about me and our lives together.”

The main downside, Peters said, is that the Pentagon doesn’t officially recognize same-sex couples when allocating medical coverage, housing and travel allowances, and other benefits.

Peters is president of the American Military Partner Association, one of several advocacy groups that says the Obama administration could act on its own to extend these benefits, even without Congress repealing the 1996 law denying federal recognition to same-sex marriages.

“We were told that once we won repeal, these types of things would be inevitable . . . but now the defense leadership is dragging its feet,” said Alex Nicholson, who was ousted from the Army under “don’t ask” in 2002 and later founded Servicemembers United, an organization for gay military personnel and veterans that pressed for repeal.

The Defense Department says it is studying the possibility of extending marital benefits to same-sex couples but has not announced a time frame. Otherwise, the Pentagon has been emphatic in declaring the repeal a success.

The reasons, said Pentagon spokeswoman Eileen Lainez, include comprehensive pre-repeal training, vigorous monitoring and enforcement of standards, and service members’ “adherence to core values that include discipline and respect.”

Last week, the Palm Center — a research institute at the University of California at Los Angeles — issued what it described as the first academic study of the impact of repeal, which it had supported. Co-authored by professors from the military academies and Marine Corps War College, the study concluded that the repeal had no broad negative impact.

“Contrary to expectations, the co-authors found evidence that repeal has improved trust among the troops, and has enabled service members to resolve problems in ways that were not possible while DADT remained law,” the Palm Center said.

Anti-gay harassment and discrimination persist, according to the study. It cited an incident in April when a squadron commander told a female officer to stop dancing with her girlfriend at a military ball, swore at the women and called them an “abomination.”

But the study noted that harassment and bias had existed before the repeal, and it contended that the problems had not worsened in the past year.

Nonetheless, some critics insist that the repeal has been disruptive and argue that the scope of the troubles is hard to gauge because some military personnel fear repercussions if they speak up.

One opponent of repeal, Elaine Donnelly of the conservative Center for Military Readiness, said Obama “has recklessly used the armed forces for unprecedented social experimentation.” She welcomed a section of the Republican Party’s new platform pledging to review military personnel policies and correct problems that might be uncovered.

— Associated Press

“The Marines he works with are completely supportive. He’s able to be honest about me and our lives together.”

Stephen Peters, former Marine discharged under “don’t ask, don’t tell”