Other experts believe a natural evolution will help women catch up to the men.
"We really need to look at the history of sports in general and women's physical fitness, which has developed so rapidly over the last 50 years," says Laura Browder, an English professor at the University of Richmond and expert on women in combat.
"If you look at Olympic records and marathon records, women are able to do so much more now than they were decades ago. The physical fitness standards in the military are such that women are very, very eager to meet them. I believe they'll rise to the challenge," says Browder, who authored "When Janey Comes Marching Home: Stories of American Women at War."
The Marine Corps announced in November it would start mandating all women perform actual pull ups as a part of their physical training regime, not the easier flex arm hang previously available to female recruits and officer candidates.
The Defense Department opened up 15,000 roles to women last year, following a trend that now allows women to serve as fighter pilots and on submarines.
"These changes have been implemented and the experience has been very positive," Panetta said.
Declaring that women are equal to men in a combat environment may also correct an issue that has given the Department of Defense a black eye. Dempsey believes that lifting the barrier on women serving in combat may help lessen the frequency of sexual assaults throughout the military.
"The more we can treat people equally, the more likely they are to treat one another equally," he said at the briefing.
Now the military is faced with finding answers to the nuanced details of introducing women formally into combat roles. The Army traditionally bolsters ranks in senior officer and non-commissioned officer ranks for a major transition, so new inductees have help along the way, a defense official said Thursday.
"In order to account for their safety and their success in [combat] units, we have to have enough of them so they can have mentors and leaders above them," Dempsey added.
This is a valuable component to breaking down these kinds of barriers.
"It is very difficult to be a pioneer," Browder says. She interviewed the first women allowed to enter a cadet class at Virginia Military Institute, who dropped out before graduating due to the pressures.
"It's not only physically challenging, you're up against a lot. All eyes are on you," she says. "Over time, more and more women will sign up and it will get easier for them on all kinds of levels."
Dempsey echoed the general benefits of introducing women into a new environment. Omitting specific details, he told reporters about his experience graduating from West Point in 1974, visiting in 1976 when the first female cadets enrolled, teaching in the early 1980s and observing it as the nation's top general.
"Academically, and physically – athletically – it was a far better place," he says. "I attribute that to opening up the academy to women."