WASHINGTON • US President Donald Trump, who aides said has been seething about news coverage of Defence Secretary James Mattis' pointed resignation letter, abruptly announced on Sunday that he was removing the Pentagon chief two months before his planned departure and installing Patrick Shanahan as acting defence secretary.
The move brings fresh instability to the Pentagon as it manages Mr Trump's sudden decisions to withdraw US troops from Syria and Afghanistan.
Mr Shanahan, a former Boeing executive who has been Mr Mattis' deputy at the Pentagon, will assume the top job on an acting capacity beginning Jan 1. But a senior administration official said Mr Trump plans to conduct a wide-ranging search for a permanent replacement and is interested in candidates from outside the administration.
Mr Trump decided hastily to remove Mr Mattis in reaction to negative news coverage, according to senior administration officials, one of whom said the President was eager to retaliate against Mr Mattis.
Another official said Mr Trump and some advisers suspected Mr Mattis of being part of a campaign to stoke negative coverage about the President.
The abrupt nature of the departure raises questions about who else might leave the Pentagon in the coming weeks, thrusting the department further into chaos.
Army Secretary Mark Esper, Air Force Secretary Heather Wilson and Navy Secretary Richard Spencer have characterised their relationships with Mr Mattis as close, and Ms Wilson has said she chose to serve in the administration specifically at the request of Mr Mattis.
In his tweet last week announcing Mr Mattis' departure, Mr Trump initially praised the secretary for serving "with distinction" and achieving "tremendous progress".
But as he consumed media coverage in the hours and days that followed, Mr Trump vented to advisers about the narrative that took hold of the revered four-star Marine Corps general and military intellectual walking out on Mr Trump because he believed the President's erratic decisions were threatening the world order.
In recent days, Mr Trump told White House aides he does not need Mr Mattis and that his defence chief was not as important a figure as others believed.
Last Saturday, he complained on Twitter that he was not getting enough credit for the Syria withdrawal: "If anybody but your favorite President, Donald J. Trump, announced that, after decimating ISIS in Syria, we were going to bring our troops back home (happy & healthy), that person would be the most popular hero in America. With me, hit hard instead by the Fake News Media. Crazy!"