Here, too, the changing nature of war seems to accelerate the pattern.
"Modern wars will be fought 360 degrees, which means women will be on the 'front lines' whether the Congress likes it or not," says retired Army Col. Dan Smith, a military analyst with the Friends Committee on National Legislation in Washington.
Though many servicemen in Afghanistan and Iraq have children, it is the mothers in the war zones who seem to raise greater concerns. (Army Pfc. Lori Ann Piestewa, the first American woman to be killed in Iraq, left two small children to be raised by their grandparents.)
Until recent years, if a woman in uniform got pregnant or adopted a child, she had to leave the service. Loren Thompson, a military analyst at the Lexington Institute in Arlington, Va., says his parentsare a good example of what happened in the past. His father was an Army colonel who served with Gen. "Vinegar Joe" Stilwell in China. His mother was an Army major on Gen. Douglas MacArthur's staff during the occupation of Japan. They met in Korea and married.
"Some time later I was conceived and Mom got the boot, even though she appealed her involuntary retirement all the way to the Senate Armed Services Committee," recalls Dr. Thompson.
While the general trend toward more rights for women in the United States has advanced steadily in recent decades, those gains aren't necessarily exportable - particularly in wartime.
Waging a counterinsurgency war in one of the world's most traditional societies is a reminder that American values cannot be the only factor shaping military policy, says Thompson.
"The first lesson of effective counterinsurgency is respect for local peoples and their cultures, so this could become a test of American flexibility," he adds.
"This is one case where it may not be feasible to honor American values and those of the people we propose to liberate at the same time," he says. "Our attitudes toward gender equality and relations between the sexes may simply be too different."