Gallagher was demoted in July after the military court found him guilty of conduct unbecoming related to a photo he staged with the body of an ISIS fighter.
In November, as the Navy prepared to review Gallagher's status, Trump ordered the branch to restore his rank and publicly forbid commanding officers from discharging him.
Secretary of the Navy Richard Spencer was forced to resign after he tried to negotiate a backchannel deal with the White House regarding Gallagher's fate.
"We're left with a question of—the Uniform Code of Military Justice is a law passed by Congress—it's not the White House's law.
And I think we've seen command influence by President Trump in a manner that if he was a general court martial authority, two-star general, we'd fire him.
McCaffrey first reached national prominence as a Trump critic following a Russian nerve-agent attack on U.K. soil in March 2018.
"It is apparent that he is for some unknown reason under the sway of Mr. Putin," the general concluded. »