Update, Aug. 30, 2017, at 2:42 p.m.: As Slate’s Mark Stern writes, Defense Secretary James Mattis’ Tuesday announcement was not necessarily the rebuke or freeze of Trump’s transgender ban that it was reported to be on Tuesday night.

Original post: Defense Secretary Jim Mattis announced Tuesday the Pentagon will not carry out President Trump’s directive to ban transgender soldiers from serving in the military, opting instead to put a hold on the White House policy pending the findings of a formal expert study on the impact of the ban. Mattis’ move is a clear rebuke of Trump wrapped in professionalism. Trump announced the reinstatement of a ban on transgender individuals serving openly in the military with the flick of a tweet in July. The president of the United States provided no notice for the dramatic policy reversal—delivered via three tweets—and offered little by way of reasoning for why the ban was being put back in place.

The only window into the president’s thinking was his reference to the “tremendous medical costs” he believed transgender troops imposed along with their “disruption.” The underlying problem for Trump, and conservatives, is the use of taxpayer dollars to provide gender transition and hormone therapy, as provided for by the Obama era policy. One month after the initial announcement, the White House sent a policy directive to the Pentagon outlining the terms for excluding transgender individuals from serving. The directive signed on Friday by Trump gave Mattis broad leeway in determining if transgender soldiers could continue to serve in some cases. The directive gave Mattis six months to implement Trump’s policy aims, which, the New York Times points out “precludes transgender people from joining the military unless Mr. Mattis, in consultation with the secretary of homeland security, ‘provides a recommendation to the contrary that I find convincing.’”

The Pentagon was apparently not consulted when Trump tweeted out his plans for the military on July 26th and the White House did not appear to do any policy due diligence on the logic and impact of its directive. Under the 2016 Obama policy change, soldiers serving in the armed forces were no longer subject to dismissal for being transgender and were free to serve openly. Mattis recently delayed the July deadline for the Pentagon to begin accepting new transgender recruits by six months to further consider the impact of the move on “the readiness and lethality” of U.S. forces. In a Defense Department memo, Mattis stated his decision to delay and review enrolling transgender troops “does not presuppose the outcome of the review.”

“Once the panel reports its recommendations and following my consultation with the secretary of Homeland Security, I will provide my advice to the president concerning implementation of his policy direction,” Mattis said in the statement on his decision to put the Trump directive on hold. “In the interim, current policy with respect to currently serving members will remain in place.”

This is not the first subtle rebuke by the Secretary of Defense of his commander in chief. Mattis was recorded during a private moment speaking to troops during what appears to be his trip to Jordan, Turkey, and Ukraine last week. “You just hold the line until our country gets back to understanding and respecting each other and showing it,” Mattis said. It was an unscripted and revealing moment that Slate’s Fred Kaplan writes shows Mattis “all but acknowledging to the servicemen and women he oversees that the country they serve is broken and that the commander in chief, whose lawful orders they have sworn to obey, has helped break it.”