The American armed services have undergone a considerable transformation since the last time the United States was engaged in a major conflict, and should war break out in the Middle East, women will play a more significant role than they ever have in our military history.

It is also probable that the long debate over whether women should be in combat will finally be ended by events: Women soldiers are in Saudi Arabia, and should hostilities break out there, they are in as much peril as American men.

Under current law, women are barred from permanent assignment by the Navy, Marine Corps and Air Force to ships and aircraft that are expected to be engaged in combat missions. The Army's policy is to bar women from "routine engagement in direct combat." The practical result of the policies is to exclude women from about half of the military jobs in the Defense Department.

Rep. Patricia Schroeder (D-Colo.) met yesterday with Marine Corps officials to find out why women Marines had been barred from going to the Persian Gulf. "We have been upset that everybody deployed women except the Marines," Schroeder said later. "They rolled up the plane and said women couldn't get on. We had them in here saying they screwed up and they're going to be deployed in the same manner."

The Women's Research and Education Institute, in a recent study of women in the armed forces, reported that women make up about 11 percent of the current military forces. The drafting of men ended in 1973, and the services were converted to all volunteers. Since then, the number of women has risen 400 percent, from 45,000 in 1973 to more than 229,000 today. The report was prepared by the staff of the institute and by Carolyn Becraft, a former Army officer who headed the Women's Equity Action League's project on women in the military for many years.

The study found that women fare very differently in the various services. Only 20 percent of Marine Corps jobs are open to women, but 97 percent of Air Force jobs and all of the jobs in the Coast Guard are open to women. The Coast Guard is under the jurisdiction of the Department of Transportation, which was headed by a woman, Elizabeth H. Dole, from 1983 to 1987.

Perhaps the most striking part of the study was its findings about the importance of black women to the armed forces. Thirty percent of all military women are black, while only 19 percent of all military men are. The Army appears to be particularly appealing to black women, and they make up 47 percent of the Army's enlisted women. One out of every five women Army officers is black.

The Navy has opened 59 percent of its jobs to women. It bars women from combat ships and aircraft, but it allows women to serve temporary duty on combat ships and to train men to fly combat planes. Five women are rated as test pilots -- more than in any other service.

In 1989, women Air Force pilots and crews participated in airlifting troops and supplies into Panama. Four women participated as copilots during the 1986 attack on Libya.

The march of women into the armed forces has occurred in many other countries that have nationals being held hostage by Iraq. In January of this year, the British Royal Navy opened seagoing positions on combat ships to women. Italy and Spain are the only NATO nations that exclude women from the military. Women in Canada and Denmark are trained as fighter pilots. The report notes the irony that the "U.S. Air Force has trained Danish women fighter pilots but will not train U.S. Air Force women pilots to fly fighter aircraft."

Declining birthrates and the progress of women around the world have worked to open up military job opportunities to women to an extent never equaled. Said Schroeder of combat, the last frontier: "We have a volunteer force. We have women who are wannabees. If you are going to deny the wannabees, then you have to go out and grab the people who don't wannabee. And I've always felt you are much better off, assuming qualifications are the same, having qualified people who want to be there than having qualified people who don't want to be there."

She pointed out that the forts in the Old West had women laundry workers. "They got shot. They got killed. It's fascinating how we've said we've protected women from combat zones, and we really haven't. At the cemetery at West Point there are women buried there who were Revolutionary soldiers. George Washington insisted that they all be paid and that they have the same benefits. You've really had women in combat since the beginning of the country. I just wished people would have the same fairness and vision that George Washington had about the whole thing."