Secretary of Defense Jim Mattis announced late on Tuesday he will begin a review of transgender military policies in conjunction with the guidance President Donald Trump sent him last week.

It’s very important to remember that when Trump sent the Pentagon the transgender policies, he gave Mattis a lot of leeway to make changes and recommendations.

Here is the full statement from Mattis:

Mattis has always stressed that he will not tolerate anything that he believes will hinder our military’s readiness on the battlefield. He did not provide a timeline on this study or how long it will take.

This is what Trump sent the Pentagon on August 25:

As you can see, Mattis is doing exactly what Trump directed him to do in his memo:

Sec. 2. Directives. The Secretary of Defense, and the Secretary of Homeland Security with respect to the U.S. Coast Guard, shall:

(a) maintain the currently effective policy regarding accession of transgender individuals into military service beyond January 1, 2018, until such time as the Secretary of Defense, after consulting with the Secretary of Homeland Security, provides a recommendation to the contrary that I find convincing; and

Yes, Trump’s policy is not supposed to go into effect until January 1, 2018 and even then it only applies to sections 2(a). Sections 1(b) and 2(b) will go into effect on March 23, 2018

Trump’s memo states that Mattis and the Secretary of Homeland Security have until February to review (emphasis mine):

By February 21, 2018, the Secretary of Defense, in consultation with the Secretary of Homeland Security, shall submit to me a plan for implementing both the general policy set forth in section 1(b) of this memorandum and the specific directives set forth in section 2 of this memorandum. The implementation plan shall adhere to the determinations of the Secretary of Defense, made in consultation with the Secretary of Homeland Security, as to what steps are appropriate and consistent with military effectiveness and lethality, budgetary constraints, and applicable law. As part of the implementation plan, the Secretary of Defense, in consultation with the Secretary of Homeland Security, shall determine how to address transgender individuals currently serving in the United States military. Until the Secretary has made that determination, no action may be taken against such individuals under the policy set forth in section 1(b) of this memorandum.