For women who have already seen combat, it is a decision that is well overdue. But for the skeptics, it is a setback that will damage the military.

The Pentagon's reported decision to lift the ban on women in combat units will take time to put into effect, but many former service members are lauding reports that the Defense Department will make the change soon.

"We have an all-volunteer force, and I think that this opens up a pool of folks who could serve in these positions," said Rep. Tammy Duckworth, an Iraq War veteran who lost both legs and the use of one arm when her helicopter crew was shot down in 2004. "Any time that we've opened up our military to performance-based service ... we've benefited as a military. This is good for the nation."

The new policy will be implemented over the next three years, and some units may apply for exemptions, a senior defense official told CNN.

Duckworth, an Illinois Democrat, said the military should open up every unit to women and see if they can complete the required training.

"If the women can't meet the standards, they don't get to graduate from the program."

U.S. Rep. Tulsi Gabbard, a Hawaii Democrat who served with her state's National Guard in Iraq, said the move is a "major step that is long overdue."

Interviewed by CNN's Soledad O'Brien, Gabbard said it's a "great recognition ... of all the women who are currently serving overseas, many of them in these combat type situations already."

Gabbard was asked whether the move is merely semantics because front lines are constantly shifting and disappearing in today's world, and women already have been in combat situations.

"I think so," Gabbard said. "When we look at, for example, two women, the first two women who earned Silver Stars since World War II, one was a military police sergeant, another was a medic. And they both were operating on the front lines per se, under fire, under extreme duress, shoulder to shoulder with their male and female counterparts, and exhibiting great courage and heroism and saving the lives of their brothers and sisters."

Julie Weckerlein, who has served more than 13 years in the Air Force and did tours in Iraq and Afghanistan, thinks the change reflects the military catching up with the times.

Some women have already gone on patrols with ground troops, helping to talk with female civilians in Afghanistan. Some submarine crews have added female officers. Women also serve as military police officers.

Women supporting supply missions have been drawn into battle in Iraq and Afghanistan, where there are no physical front lines.

Now, Weckerlein said, "people will be able to serve in the career fields they are qualified for, and they won't be turned away because of their gender."

Weckerlein went to Iraq in May 2007 as part of then-President George W. Bush's "surge policy" to put more troops on the ground.

"The first death I experienced was a woman, within the first few weeks I was in Iraq," she said.

It was June 25, 2007, and her outpost in Nasir Lafitah came under mortar fire. In the attack, Army Staff Sgt. Trista Moretti of South Plainfield, New Jersey, was killed. Moretti, 27, was assigned to a support battalion.

Days later, Weckerlein came under mortar fire again. This time, her comrade -- a cameraman -- was injured.

Even though her deployment orders said Qatar, she spent weeks in the summer of 2007 shuttling between bases in Iraq and Afghanistan.

Like many women in the military, Weckerlein didn't get the additional combat training because she was in what was considered a support role.

"I really want to stress there was no bitterness. It was a reflection of the times, and I feel like we are now getting with the times," she said. "I see this as a positive thing."

Not everyone agrees.

Rep. Tom Cotton, an Arkansas Republican, has said he doesn't think women are physically capable of combat duty.

"To have women serving in infantry ... could impair the mission essential task of those units, and that's been proven in study after study," he told radio host Laura Ingraham this month. "It's nature -- upper body strength and physical movements and speed and endurance and so forth."

Jonn Lilyea, one of the founders of the military blog "This Ain't Hell," wrote that he thinks it was an "ill-considered decision."