Women make up 15 percent of the 1.4 million active-duty service members. Annette Deener, a retired brigadier general in the Maryland National Guard, said women have earned the opportunity to compete for combat jobs.
"Since 9/11, women have really proved themselves on the battlefield," said Deener, now chief of staff of the Maryland Military Department. "I think that influenced the decision."
Fifteen female members of the Maryland Guard have earned the Combat Action Badge in Iraq or Afghanistan. The badge is awarded to noninfantry soldiers who have actively engaged or been engaged by the enemy.
About 20 percent of the jobs in the 6,400-member Maryland National Guard are restricted to men, including infantry, cavalry and Special Forces specialties.
Deener, who joined the now-defunct Women's Army Corps in 1975, called the decision to open these jobs to females "great — as long as women can meet the same standards as men."
Panetta said the services would set clear, "gender-neutral" standards for all military occupations. It would be up to Congress to decide whether to require women to register for the Selective Service on turning 18.
While Panetta and Dempsey announced the decision, President Barack Obama issued a statement of support.
"Our armed forces have taken another historic step toward harnessing the talents and skills of all our citizens," he said. "Today, every American can be proud that our military will grow even stronger with our mothers, wives, sisters and daughters playing a greater role in protecting this country we love."
Obama has nominated former Sen. Chuck Hagel, a Republican, to succeed Panetta as defense secretary.
The decision to lift the combat exclusion for women was not welcomed in all corners.
"The people making this decision are doing so as part of another social experiment, and they have never lived nor fought with an infantry or special forces unit," said retired Lt. Gen. Jerry Boykin, a former commander of Delta Force.
Such units, he said, must endure sustained operations for extended periods in primal living conditions with "no privacy for personal hygiene or normal functions." The decision to integrate the genders in such units, he said, "places additional and unnecessary burdens on leaders at all levels."
First Lt. Gregg Zavadsky of the Maryland National Guard said he trusted that commanders had thought through the decision and concluded that it was in the best interest of the military.
"It's going to be a change," he said. "But soldiers are trained to adapt to any situation. I don't think it's going to be an issue.
"I know a lot of women who are capable of serving in these combat arms positions."
Kupcho, stymied in her ambition to drive tanks in combat, said she is satisfied with her career as a public affairs officer for the Maryland Guard, a role that took her to Afghanistan in 2011 and 2012.
While she no longer harbors dreams of joining an armored unit, she applauded the decision that would make it possible.
"It's a great opportunity for women who want to pursue these jobs," she said. "It's going to level the playing field."