Eric Vidal/REUTERS
Defense Secretary James Mattis will leave Jan. 1 instead of February and his deputy, Patrick Shanahan, will become acting secretary, President Trump announced Sunday. Mattis announced his resignation Thursday over President Trump's abrupt decision to pull some 2,000 U.S. troops from Syria, where they had been fighting ISIS alongside regional allies. Mattis was originally expected to remain in his position until February to ensure a smooth transition. It was not clear why the timetable was accelerated, but the president tweeted, “I am pleased to announce that our very talented Deputy Secretary of Defense, Patrick Shanahan, will assume the title of Acting Secretary of Defense starting January 1, 2019. Patrick has a long list of accomplishments while serving as Deputy, & previously Boeing. He will be great!”