U.S. Defense Secretary Leon Panetta has lifted the ban on women serving in military combat positions.
Panetta said woman have "proven their ability to serve in an expanding number of roles" in the military services, so the change will strengthen U.S. armed forces' ability to win wars.
Speaking at a Pentagon ceremony in remembrance of civil rights leader Martin Luther King Jr., Panetta said the U.S. military is more capable and more powerful "when we use all of the great diverse strengths of the American people.''
The new policy could open more than 230,000 battlefront posts to women in the U.S. Army, Navy, Air Force and Marines.
Serving in combat positions has always been an advantage for soldiers' advancement through the ranks, and women have long complained about their inability to fill such jobs.
Physical requirements for troops applying for combat duty will not be waived for women in the future, officials said, and it could develop that some battlefield roles will be restricted in the future. Chiefs of the separate military services will have three years to study that issue.
Those who oppose combat duty for women have questioned whether whether they have the necessary strength and stamina for certain jobs, or whether their presence might hurt unit cohesion. Retired Army general Jerry Boykin is now executive vice president of the Family Research Council, a Christian group that promotes conservative social values. He criticized the Pentagon announcement as "another social experiment" that will place unnecessary burdens on military commanders.
Women comprise about 14 percent of the 1.4 million people on active duty in the U.S. military. More than 280,000 women have served in Iraq or Afghanistan or neighboring nations since 2001. Of the more than 6,600 U.S. service members who have been killed, 152 have been women.