The faces of U.S. soldiers in combat are beginning to change, but women aren’t just newly permitted on the front lines of the battlefield. They’re also at the forefront of the policy debate, with three of six Senate Armed Services subcommittee gavels now held by women.

Democratic Sens. Kirsten Gillibrand of New York, Jeanne Shaheen of New Hampshire and Kay Hagan of North Carolina have taken the helms of the subcommittees on Personnel, Readiness and Management Support, and Emerging Threats and Capabilities, respectively. Two of those panels — Readiness and Emerging Threats — also have female ranking members in Republican Sens. Kelly Ayotte of New Hampshire and Deb Fischer of Nebraska.

The changing composition of one of Congress’ most powerful committees is already beginning to shift the once-rigid conversation on the military, too. On Wednesday, Gillibrand will hold her first hearing as chairwoman — on sexual violence in the military.

“Having more women chairing subcommittees on the Armed Services Committee will make a difference … the nature of the issues that will be explored, the type of hearings that will be held, will cover a broader base of issues,” she said.

Gillibrand, who was appointed to the House Armed Services Committee when she first arrived in Washington in 2007, brings years of experience on the issue of violence in the military to the subcommittee and says her time in the House taught her about the more “holistic” approach women can bring to the national security conversation.

“Women House members raised issues that hadn’t been raised,” Gillibrand said. “Instead of just the typical conversation on how many ships do we build, how many aircraft and equipment-oriented questions, there was a whole area of focus on well-being of the troops, and why was the divorce rate and the domestic violence rate higher than it had ever been, and what were we doing for PTSD and traumatic brain injury. … It made a difference in terms of holistic approach.”

For years, conversation on sexual violence in the military has been dominated by the House, where Reps. Michael R. Turner, R-Ohio, and Niki Tsongas, D-Mass., founded the Military Sexual Assault Prevention Caucus.

Indeed, senators had been so reluctant to discuss sexual violence in the military — where the Department of Defense estimates 19,000 assaults occurred in 2011 — that when the director of “The Invisible War” tried to interview lawmakers in 2010, only House members would go on camera with him, according to Greg Jacob, a former Marine and policy director at the Service Women’s Action Network.

Former Defense Secretary Leon E. Panetta later cited the acclaimed documentary as key to his decision to implement new rules regarding sexual assault.

“This is the first real, visible thing that the Senate has done on this issue in a long, long time, and we’re hoping that this moves the conversation forward,” Jacob said of Wednesday’s hearing, where SWAN’s executive director will testify.

Jacob noted that the most important shift, however, might come from outside Gillibrand’s Personnel Subcommittee, where women have been more vocal, and on the other subcommittees that long have been considered more prestigious.

“Traditionally, in the past, the Personnel subcommittees are the subcommittees that have been viewed as dealing with these ‘soft’ issues — there’s a perception among the larger committee that it’s not really a hard, substantive committee, [whereas] the Readiness and Emerging Threats subcommittees are seen as the ‘nuts-and-bolts, bullets-and-beans and bad guys’ panels,” Jacob said. “These women are not being used as window dressing. They are dealing with these really hard, very strategic, nuts-and-bolts national defense issues also.”

Shaheen, the Readiness panel chairwoman, said she believes women taking key roles does lead to new questioning of old policy because, like with any issue in Congress, members bring their own experience to the table.

The New Hampshire Democrat said she plans to focus on energy policy and how effective energy use can be a part of the military’s overall readiness policy.

“I don’t know to what extent that’s been raised,” Shaheen said. “We all bring to whatever we’re doing our own experiences, and as women, those experiences are usually different than men’s. Witness what [Sen.] Claire McCaskill has had to say about having been a prosecutor and the issue of sexual assault, so I do think there is a difference.”

Indeed, McCaskill and Shaheen were among the female senators who lashed out at military leaders last week, when news broke about a decision by an Air Force general to overturn a jury’s guilty verdict against a military pilot accused of rape. That issue is almost certain to surface in Gillibrand’s Wednesday hearing.

Fifteen percent of people in the military are women, and that number will grow to 20 percent within the next three to four years, Jacob said.

Gillibrand sees a direct connection between the decision to allow women in combat and future incidents of sexual violence.

“One question that has been raised is, will that help alleviate the number of sexual assaults by having women in combat, so there would be less overall discrimination in the armed services,” Gillibrand said. “That’s a question we don’t know the answer to, but it’s an interesting question, and hopefully, as women continue to elevate themselves in terms of rank and authority and supervising capacity, there will be less and less tolerance for this kind of behavior.”

Senate Armed Services Chairman Carl Levin, D-Mich., said he believed women taking elevated roles in his committee “intensifies an awareness that’s been growing about the role of women in the military.”

And that’s certainly a responsibility taken seriously by Senate women, who are boosted this year by a historic class of 20 members — seven of whom sit on Armed Services.

As Shaheen said, there are “not many shrinking violets.”