The survey was carried out in 2012 by the think tank CNA, but the results were withheld from the public as the Defense Department announced in January 2013 that it would open all combat jobs following a lengthy research period that ended last fall. Defense Secretary Ashton B. Carter made the change official in December, giving the services until this spring to begin fully integrating women.
The survey results, released to The Washington Post through the Freedom of Information Act, were not among the dozens of documents detailing the Defense Department's research on the subject that were released by the Pentagon following Carter's announcement in December. They are outlined in a 338-page report titled "Assessing the Implications of Possible Changes to Women in Service Restrictions," and may in part explain why the Marine Corps was the only service to petition Carter to keep some of its combat jobs closed, including infantryman and reconnaissance man.
"Overall, we found that, among male respondents, those in the officer ranks from second lieutenant (O-1) through colonel (O-6) and those in the enlisted pay grades of corporal (E-4) and sergeant (E-5) were consistently the most opposed to prospective policy changes," the report said.
Among women, officers who obtained the rank of at least major were the most likely to be in favor of opening all combat jobs to women. About 53 percent of them signaled support. About 51 percent of lower-ranking officers said there were in favor of women serving in combat arms jobs, but the number dipped to about 41 percent of female corporals and sergeants and about 37.5 percent of enlisted staff noncommissioned officers.
Opposition was stiffest among Marines who have served in the all-male infantry, which regularly performs long combat patrols on foot while carrying up to 100 pounds of weapons, equipment and armor. The study found that 76.5 percent of Marines who served in an infantry unit were opposed to opening ground combat jobs to women. Opposition to opening all combat jobs to women was still significant among male Marines who did not serve in ground combat assignments, with 22.4 percent in favor of including women and 56.4 percent opposed.
The survey also highlighted a variety of cultural issues. Nearly 90 percent of male Marines said they were concerned about intimate relationships between Marines in the same combat unit becoming a problem, and more than 80 percent said they were concerned about false sexual assault allegations, fraternization and women receiving preferential treatment.
The top concerns listed by female Marines were enemy forces targeting them as potential prisoners of war, the risk of sexual assault or harassment and intimate relationships becoming a problem. More than 70 percent of female Marines who took the survey cited each of those as an issue.
The survey was requested by Marine Gen. Joseph F. Dunford, a career infantry officer who was then the assistance commandant of the Marine Corps. Dunford went on to become the top U.S. commander in Afghanistan and then commandant of the Marine Corps. He became chairman of the Joint Chiefs of Staff last fall. Many of the same issues were raised in the results of a survey carried out among elite members of U.S. Special Operations Command, including Navy SEALs, Army Green Berets and Special Operations Marines, released in December.
It is not believed that any comparable survey of Marines has been carried out since 2012.
A Defense Department spokeswoman, Marine Lt. Col. Gabrielle Hermes, said the study was not released with other research in December because the Pentagon focused on publishing online all studies commissioned as a result of then-Defense Secretary Leon Panetta rescinding the rule banning women from all ground combat assignments in January 2013. The Marine Corps survey was mandated by the 2011 National Defense Authorization Act, which directed reviews of the old policy, and "informed earlier decisions," Hermes said.
Last fall, Marine officials said that an extensive research project carried out involving about 300 male Marines and 100 female Marines found that combat units integrated with female Marines typically did not move as quickly or shoot as accurately. Women also were more than twice as likely to suffer injuries as a result of carrying heavy combat loads, the study found.
But the study was criticized by advocates of gender integration, including Navy Secretary Ray Mabus, who said the Marines erred in focusing on what the average woman could do in combat, rather than elite performers. Mabus has continued to trade barbs on the issue, including with some senators during a Senate Armed Services Committee hearing last month.
Some critics also have said that the Marine Corps is due for a culture change. Among them are Lt. Col. Kate Germano, who was relieved of command at Parris Island, S.C., after pushing her staff to demand the same effort from male and female recruits. She has argued repeatedly in recent months that the service does not hold women to the same standards.
The new Marine commandant, Gen. Robert B. Neller, has promised the service will carry out the changes and fully integrate.