Nearly one in four males in the U.S. Marine Corps said they would leave the service if women were involuntarily posted in combat positions, according to the executive summary of a little-known survey commissioned by Marine Corps leaders and obtained by the Free Beacon.

A similar number of Marines of both sexes said they would not have enlisted in the corps if this had been policy at the time.

Twenty-three percent of both male and female Marines "said that they would not have joined" if women were involuntarily placed onto the front lines of combat, such as in the infantry, according to a summary of the survey provided to the Free Beacon.

Retention rates also could be affected at a time when the Marines are shrinking the force to cope with budgetary constraints.

Twenty-two percent of males who were surveyed said they "likely would leave the corps at their next opportunity" if women were involuntarily placed into primary combat roles.

Seventeen percent of females surveyed provided a similar answer, a number the report’s author suggests is surprisingly high.

The findings overwhelmingly reveal that the introduction of women into combat roles could pose a serious quandary for the nation’s fighting forces, which are struggling to adjust to a recent Pentagon order allowing women to fill combat positions.

The Pentagon announced last month it is in the process of removing restrictions on women joining front-line combat units. Women currently are banned from direct combat, although female troops have been in war zones for years.

Just how dire the situation could become remains unclear.

The Marines would only release to the Free Beacon an "executive summary" of the survey, which was conducted from May 30, 2012, to Aug. 31, 2012, prior to the Obama administration’s decision to reverse the longstanding policy of excluding women from most combat positions.

A Marine spokesperson told the Free Beacon via email that a Freedom of Information Act request would be needed to obtain any more information.

Asked why the full results of the survey have not been released, the spokesperson said, "It has not yet gone through a formal legal review for public release and may contain sensitive information (i.e. personally identifiable information)."

Sizable percentages of women indicated their willingness to serve in a combat position, the survey found.

Thirty-one percent said they would be "interested" in moving to a major combat role while 43 percent said they "would have chosen a combat arms" position when they joined the Corps.

Another 34 percent said they would volunteer for the Marine’s Ground Combat Element (GCE), a first-attack land force comprised of combat arms and communications.

Male and female Marines had differing concerns over sexual integration of combat forces.

"Both male and female respondents mentioned intimate relationships between Marines and male Marines feeling obligated to protect female Marines among their top five concerns about allowing female Marines to be classified into ground combat," the survey states.

Men also said they were apprehensive about "limited duty affecting unit readiness before deployment, Marines fearing false sexual harassment or assault allegations, and fraternization/some Marines getting preferential treatment," the survey states.

"Female respondents specifically mentioned concerns relating to personal hygiene, acceptance, and physical abilities," the survey found.

Potential impacts to recruiting and retention appear to be a central concern of Marine leaders.

As the corps prepares to shed more than 20,000 active duty positions in the coming years, opposition to the new policy of placing women in combat roles could deter new recruits and encourage enlisted ones to leave.

Seventeen percent of male Marines said "they would not have joined the corps" if "women could have volunteered to serve in combat arms," the survey found.

Just a small percentage of female Marines said they would have been deterred by voluntary combat postings, meaning women would only serve in a combat role if they explicitly asked.

"If women could have volunteered to serve in combat arms PMOSs [Primary Military Occupational Specialties] when they joined the Marine Corps, 17 percent of male Marine respondents indicated that they would not have joined the corps compared with 5 percent of female Marine respondents," the study states.

PMOS is military jargon for a service member’s primary skill set.

Smaller numbers appeared to object to women voluntarily serving in the Marine’s Ground Combat Element.

"Thirteen percent of men and three percent of women said that they would not have joined the corps if female Marines could have volunteered for GCE unit assignments," according to the survey.

Those numbers increased substantially when Marines were asked about women involuntarily being placed into these roles.

Additionally, the survey found that some critical Marines are more likely to leave the corps due to the policy changes.

Corporals and lance corporals "were most likely to say that policy changes would prompt them to leave the Corps at their next available opportunity," according to the survey. "This may be viewed as particularly problematic because lance corporals and corporals constitute the bulk of the first-term reenlistment population."

Still, there are many unknowns in the initial information the Marines released.

Few concrete numbers are provided, making it impossible to determine just how many Marines responded.

Additionally, the data is presented in a condensed and opaque manner that prevents readers from determining the exact number of Marines who have concerns about allowing women to serve in combat positions.

The Free Beacon submitted a FOIA request to obtain the full survey Thursday afternoon.