Yesterday Secretary of Defense Jim Mattis issued a Statement (full text) on the manner in which he intends to implement President Trump’s recent Memorandum barring enlistment of transgender individuals in the military and calling for a study of how to deal with transgender individuals currently serving. Mattis said in part:Our focus must always be on what is best for the military’s combat effectiveness leading to victory on the battlefield. To that end, I will establish a panel of experts serving within the Departments of Defense and Homeland Security to provide advice and recommendations on the implementation of the president’s direction. Panel members will bring mature experience, most notably in combat and deployed operations, and seasoned judgment to this task. The panel will assemble and thoroughly analyze all pertinent data, quantifiable and non-quantifiable…. 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. In the interim, current policy with respect to currently serving members will remain in place.