The New York Times nytimes.com The New York Times Friday, Dec 21, 2018 | View in browser Good morning, following the aftermath of an extraordinary day in Washington, including an impending government shutdown and the resignation of Defense Secretary Jim Mattis. also covering the reopening of Gatwick Airport near London this morning. By Chris Stanford A government shutdown looms President Trump refused on Thursday to sign a stopgap measure to avert a government shutdown, saying that any spending bill must include $5 billion for a wall on the southwestern border. Without a deal, a partial shutdown would begin at midnight tonight. House Republicans approved a version of the bill on Thursday night that included money for the wall, but it s almost certain to fail in the Senate today. Why it matters: If funding expires, nine government departments including Homeland Security and the Justice and State Departments would close, and more than 420,000 federal employees would have to work without pay. Here s what else to expect. The Daily: On today s episode, our deputy Washington editor explains the showdown. President Trump and Defense Secretary Jim Mattis attended the annual Army-Navy college football game this month. Tom Brenner for The New York Times Defense secretary quits over rift with president A day after President Trump said he would withdraw American troops from Syria, Jim Mattis, a retired four-star Marine general, said he would leave the Pentagon in February. In his resignation letter, Mr. Mattis condemned Mr. Trump s rejection of international alliances and emphasized the importance of challenging Russia and China, which he wrote wanted a world consistent with their authoritarian model.Read his letter. News analysis: The Syria withdrawal is one of several announcements this week that demonstrate Mr. Trump s unswerving conviction that his political survival depends on securing his conservative base,one of our White House correspondents writes. Catch up: Mr. Mattis is the third member of Mr. Trump s cabinet to resign or be forced out in less than two weeks. Here s a look at the turnover at the top of the accountistration. U.S. withdrawal shakes up the Middle East President Trump s decision to bring home the 2,000 American troops in Syria clears the way for Iran to expand its influence in the region and leaves Israel isolated. President Vladimir Putin of Russia praised Mr. Trump on Thursday, saying, Donald s right, and I agree with him.Moscow and Washington have supported opposite sides in the Syrian war. The reaction: America s Kurdish allies in Syria were upset by the decision and are said to be discussing the release of 3,200 Islamic State prisoners. Closer look: We examine the winners and losers from an American withdrawal. Notable: At the same time Mr. Trump made the decision about Syria, he also decided to withdraw about half of the 14,000 troops stationed in Afghanistan, two defense officials said. Potential threats to the special counsel s inquiry Matthew Whitaker, who was named acting attorney general last month, has cleared himself to supervise the investigation by the special counsel, Robert Mueller, according to a letter the Justice Department sent to Senate leaders. Ethics specialists at the department had recommended that Mr. Whitaker recuse himself from the investigation into Russian election interference, as his predecessor Jeff Sessions had done. The news came soon after the disclosure that President Trump s nominee for attorney general, William Barr, had written a memo in June criticizing Mr. Mueller for focusing on whether Mr. Trump had committed obstruction of justice. Read: The letter about Mr. Whitaker and Mr. Barr s memo. Why it matters: The developments raise questions about Mr. Mueller s ability to complete his work without interference. Now, a break from the news If there were creatures on Uranus and I don t think there are seasonal affective disorder would be a lifetime thing,the planetary scientist Heidi Hammel told The Times. That s it for this briefing. Thanks to all the readers who submitted Back Story ideas yesterday. There were more Christmas-related ones than we be able to get to this year, but we add them to the list for 2019. Have a good weekend. Chris Thank you To Aisha Harris for mining our cultural coverage and Kenneth R. Rosen for curating Smarter Living. Mike Ives, a Hong Kong-based reporter, wrote today Back Story. You can reach the team at briefing@nytimes.com. P.S. mini crossword puzzle, and a clue: Parter of the Red Sea (5 letters). You can find all our puzzles here. Readers looked up more than 18,000 cities and towns in our feature How Much Hotter Is Your Hometown Than When You Were Born Today's Front Page