Staff Sgt. Patricia King is the first openly transgender infantry soldier as well as the first enlisted female infantry soldier in U.S. military history. And after 19 years serving her country, she is angry.

“This is the defense of the indefensible,” she said of the Defense Department’s March 12 memo outlining a new policy regarding transgender military service.

The policy allows currently serving transgender troops and service members who have already received a diagnosis of gender dysphoria to continue to serve in their preferred gender. But after April 12, when the policy goes into effect, no one with gender dysphoria who is taking hormones or has transitioned will be allowed to enlist.

Further, any currently serving troops diagnosed with gender dysphoria after April 12 will have to serve in their sex as assigned at birth and will be barred from taking hormones or getting gender-affirming surgery.

According to the Defense Department, the policy is not a ban on transgender service.

“Transgender individuals are not excluded from military service, and DOD policy specifically prohibits discrimination based on gender identity,” the DOD website states. “But all persons, whether or not they are transgender, must meet all military standards, including the standards associated with their biological sex. Waivers or exceptions to these standards may be granted on a case-by-case basis.”

From left, transgender military members Navy Lt. Cmdr. Blake Dremann, Army Capt. Alivia Stehlik, Army Capt. Jennifer Peace, Army Staff Sgt. Patricia King and Navy Petty Officer Third Class Akira Wyatt, are briefed about hearing procedures before the start of a House Armed Services Subcommittee on Military Personnel hearing on Capitol Hill in Washington, Wednesday, Feb. 27, 2019, as the Trump administration pushes to ban transgender troops. (AP Photo/Manuel Balce Ceneta) Manuel Balce Ceneta / AP file

King, however, said the DOD’s policy “is nothing short of a ban, regardless of whatever political language might be used.”

“This is telling qualified people they are not allowed to serve,” she said. “That is the definition of a ban.”

King said the new policy will affect everyone in the military from medical providers who will now have to choose between providing transition-related care and protecting a transgender soldier’s career, and unit leaders who may have to advise those they command not to be themselves if they wish to remain in the military.

And for service members, King said they will be “forced to violate their own integrity in order to continue to serve.”

Capt. Jennifer Peace, currently assigned to the Defense Intelligence Agency as executive officer in the Iranian division, has served in the military for 15 years, many of those as openly transgender.

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Peace told NBC News the proposed implementation plan is “an unfortunate step backwards for diversity and inclusion in the military” and will have a negative impact on currently serving trans people.

“This is the enforcement of a presidential tweet that trans people have no place in the military,” Peace said. “As senior leaders look at trans individuals, I fear they are going to see this as military directive that trans people have no place in the military, and I think it’s going have an impact on their career.”

LGBTQ military advocates roundly criticized the new policy, calling it “horrific” and “cruel.”

“This is the start of an incredibly dark chapter in our nation’s history as the Trump-Pence administration moves to implement an unconscionable ban on our brave transgender service members and qualified recruits who want to serve,” Ashley Broadway-Mack, president of LGBTQ military family group American Military Partner Association, said.

“This horrific policy is even more cruel than ‘don’t ask, don’t tell,’ because the Pentagon explicitly told these service members it was finally safe to come out — and now they are being targeted for discrimination,” Mack added. “We emphatically condemn this unconscionable transgender military ban, because it undermines military readiness, destroys unit cohesion, betrays our service members and is based on nothing more than blatant bigotry."

Navy Lt. Cmdr. Blake Dremann is the president of the LGBTQ military group Sparta and one of five service members who, along with King and Peace, testified before Congress about transgender military service. He said he and his organization “stand firmly with our members and the thousands of transgender troops serving bravely across the globe.”

“While the new policy may go into effect soon, it does not remove or lessen the contributions we continue to provide in the defense of our nation,” Dremann said. “We look forward to a time when service members are judged solely on their capability to complete the mission. We will continue to work to make that a reality."

Peace said that similar to what occurred under "don’t ask, don't tell," transgender service members will withdraw from military social life.

“What you’re going to see with all these trans troops, 14,000 service members, are going to go back to a place where they can’t be part of the military family,” Peace lamented. “You can’t talk about what you did that weekend or your spouse can’t come to the company baseball game. You feel left out. You feel like an other.”

Peace and King believe the policy will further depress the number of willing recruits at a time when the military is struggling to meet its targets. Peace said potential recruits that value diversity and inclusion “are not going to look to the military now,” and the military will be “recruiting from a smaller talent pool.”

King said that “every unit is under-strength right now.”

“Every time we lose a person for any reason that is a position that is not easily refilled,” she explained. “That is an extra job that somebody else has to do that’s a hole on the battlefield that is not filled.”

Peace said, “In the end, this is going to hurt readiness and going to hurt units, and it’s going to hurt soldiers.”

LEGAL BATTLE ‘FAR FROM OVER’

There are currently four lawsuits pending against the new policy. The Supreme Court stayed two injunctions in January, and last week U.S. District Judge George Russell in Maryland lifted a third injunction. An injunction issued by a district court in D.C. still technically remains in effect, however, until the issuance of mandate. As a result, the release of the memo came as a shock to some advocates who question whether, with its publication, the government is in violation of a court order.

“Not only does the Trump-Pence transgender military ban violate the Constitution, but now the administration is also defying a court order,” Jennifer Levi, director of the Transgender Rights Project at LGBTQ legal group GLAD, said in a statement. “With brazen disregard for the judicial process, the Pentagon is prematurely and illegally rolling out a plan to implement the ban when a court injunction remains in place prohibiting them from doing so.”

The legal battle is “far from over,” according to Shannon Minter, legal director of the National Center for Lesbian Rights.

“All four cases are proceeding,” he said. “Just because an injunction is lifted, doesn’t mean case is over.”

Outside the courtroom, many advocates support the passage of legislation that would prevent the ban from taking effect.

“Congress must act now and secure the fate of nearly 15,000 transgender troops,” Harper Jean Tobin, director of policy for the National Center for Transgender Equality, said in a statement. “History is watching Congress and will judge them harshly for inaction. That is why we must act swiftly to protect transgender troops, our military, and the dignity of our own legacy.”

Minter encouraged LGBTQ advocates and “everyone who cares about the integrity of our military” to “contact your representatives and tell them to support this legislation.”

As for Peace and King, they want the chance to speak before the Senate Armed Services Committee. “Nothing changes people’s minds more than a conversation,” Peace said. “That act of telling your story is so powerful.”

Peace said military leaders and policy makers often have “discussions about us” but do not “include us in the discussion.” Peace, who during her testimony before the House Armed Services Military Personnel Subcommittee, called the ban a “policy based in bigotry,” said it has not discouraged her from continuing to serve in the military. “If you care about something to want to see it change, you have to be the type of leader you want to see.”

King, who is close to retirement, said: “It’s so hard to be leaving the military. A year ago I felt comfortable saying it was time to retire, but now as I get ready to retire that is no longer so.”

“I know we are facing an uphill battle," King said, but “my goal is to right this wrong."

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