Military history was made as two women passed the U.S. Army's grueling 62-day Ranger Course in Fort Benning, Ga. (Reuters)

When 1st Lt. Shaye Haver and 1st Lt. Kristen Griest became the first women to complete grueling Army Ranger training — among the most intense and demanding that the military has to offer — the Army heralded it as proof that every soldier could reach her full potential amid a growing call for equality.

But with the strides made by women in uniform, there have also been setbacks. For example, 18 other women were accepted into the first phase of Army Ranger training with Griest and Haver. Yet they were the only ones who made it through.

And on Friday, the Navy announced that the first woman to begin the process for elite Navy SEAL training has withdrawn herself from the applicants pool, according to the Associated Press. The woman, whose identity the Navy will not disclose, dropped out of a summer course for officers who want to be selected for the SEALs. She was the only woman in the pipeline. Navy media officials did not immediately return a message seeking comment.

The SEAL Officer Assessment and Selection program that she was in is open to Naval Academy midshipmen and Navy ROTC cadets before their senior year.

According to the Associated Press, the three-week program in Coronado, Calif., tests physical and psychological strength, water competency and leadership skills. Sailors must complete it to be selected to take part in SEAL basic training.

That basic training, which lasts six months is so arduous that 75 percent of candidates drop out by the end of the first month.

The successes and failures of women in the military’s most taxing units is part of a steady march toward integration of the country’s armed services.

The efforts followed demands for equal treatment after thousands of American servicewomen served in the Iraq and Afghanistan wars, including many killed or wounded in service, according to the Associated Press.

In 2013, then-Defense Secretary Leon E. Panetta said he was rescinding a long-standing ban on women serving in ground combat units, and told commanders to investigate how to fully integrate the armed forces. But even then about 10 percent of military jobs remained closed to women.

That changed in 2015 when Ash Carter, once Panetta’s deputy at Defense, directed the military branches to open all military jobs to women who qualify, including access to the most elite units, The Washington Post’s Dan Lamothe reported.

The move has, at times, divided military leaders, Lamothe wrote:

Carter’s move has proven controversial with critics who question whether full gender integration could weaken the military or cause unnecessary distractions. But proponents, including Carter, have said that if women can meet all requirements for a job, they should be allowed to do so and could in fact boost combat effectiveness.

Further stoking the debate, in September 2015, a Marine Corps study designed to compare how men and women do in combat found that female service members were injured twice as often as their male counterparts, fired their infantry weapons with less accuracy and were not as good at removing wounded troops from the battlefield.

But according to a Washington Post article by Ernesto Londoño, advocates and experts “believe lifting the ban will go a long way toward changing the culture of a male-dominated institution in which women have long complained about discrimination and a high incidence of sexual assault.”

Navy SEAL trainees carry inflatable boats at the Naval Amphibious Base Coronado in Coronado, Calif. in 2009. (Denis Poroy/AP)

According to the Associated Press, another woman has set her sights on becoming a Special Warfare Combatant-Craft Crewman, another job that recently opened to women.

They often support the SEALs but also conduct missions of their own using state-of-the art, high-performance boats. She has started the various evaluations and standard Navy training.

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