The memorandum said individuals with a history of gender dysphoria, defined as "those who may require substantial medical treatment, including through medical drugs or surgery," are disqualified from military service "except under certain limited circumstances." Those who are currently in the United States military may remain in the ranks, but the Pentagon could require them to serve according to their gender at birth.

In a memo to the president, Defense Secretary Jim Mattis cited "substantial risks" about military personnel who seek to change or who question their gender identity. He found that individuals with a history or diagnosis of gender dysphoria presented a risk to military effectiveness and "could undermine readiness, disrupt unit cohesion, and impose an unreasonable burden on the military that is not conducive to military effectiveness and lethality." This new policy will enable the military to apply well-established mental and physical health standards—including those regarding the use of medical drugs—equally to all individuals who want to join and fight for the best military force the world has ever seen.

Mattis suggested three exceptions: (1) If a person diagnosed with gender dysphoria can demonstrate a period of at least 36 months where they no longer suffer from the psychological condition; (2) Those diagnosed with gender dysphoria who do not seek to "transition" (receive hormone drugs and undergo plastic and other surgery), and are deployable, may also serve; and (3) Those who have already been serving prior to the effective date of the new policy will not be discharged.

Two U.S. district courts, one in the District of Columbia and one in Maryland, previously blocked enforcement of President Trump's proposed August 2017 ban on "transgender" persons in the armed services. According to the Defense Department, those courts required the branches to begin allowing such recruits to sign up for military service. A third order by a U.S. District judge also allowed the state to challenge the ban, stating that Washington has an interest in protecting its residents from discrimination.

In the August 2017 order, President Trump reversed policies put in place by the Obama administration in June 2016. Those Obama administration policies themselves reversed long-standing military rules against "transgender" people serving in the U.S. Armed Forces. Prior to June 2016, "transgender" people were not permitted to enlist in the military and members of the military who identified themselves as "transgender" were discharged.  Obama's Department of Defense announced in June 2016 that openly "transgender" people would be permitted to enlist in the military as of January 1, 2018 and those already in the military could not be discharged. This 2018 policy announced by President Trump is based upon the study and findings of the Defense Department in the memorandum released by Defense Secretary Mattis.

"I commend President Trump for refocusing the military's mission to emphasize readiness and unit cohesion," said Mat Staver, Founder and Chairman of Liberty Counsel. "The report from the Defense Department concludes that there are substantial risks to military effectiveness and readiness regarding people who have gender dysphoria. The military is not a social club but rather a fine-tuned fighting machine of men and women who defend our freedom. It is not a right but a privilege to serve," said Staver.

Staver added, "The duty of military officers is to appropriately lead and prepare their personnel to serve and protect, and they cannot do that when there is confusion, dysfunction and distraction." 

Liberty Counsel is an international nonprofit, litigation, education, and policy organization dedicated to advancing religious freedom, the sanctity of life, and the family since 1989, by providing pro bono assistance and representation on these and related topics.