WASHINGTON • US President Donald Trump risks reviving the strife and turf battles that characterised his West Wing before Chief of Staff John Kelly's arrival, after announcing that the retired Marine general would depart by the end of the year.
Mr Kelly's authority, drawn from more than 40 years in the military, helped him tamp down infighting that broke out between factions of Mr Trump's administration almost from the day he took office.
In his absence, several White House aides fear that independent-minded senior officials and Cabinet members may once again seek to fill the vacuum.
Mr Trump said on Saturday that he will name a successor within days. The most likely replacement is Vice-President Mike Pence's top aide Nick Ayers, a young political operative who has largely kept Mr Pence out of the daily drumbeat of drama that has been a hallmark of Mr Trump's presidency.
But for Mr Trump, the job of chief of staff is almost the opposite - how to maintain order under a boss who always seeks to be the story, often through his Twitter feed.
Mr Kelly gave up trying to control Mr Trump's tweets, and his most notable success was breaking up warring factions and limiting unscheduled visitors to the Oval Office.
Mr Ayers, who already has West Wing detractors, may struggle to keep those forces at bay.
The political stakes for the White House are rising as Democrats take control of the House and federal prosecutors inch closer towards implicating the President in crimes related to his election.
Mr Ayers, a 36-year-old with a boy band-style mop of blonde hair and a southern drawl, lacks the respect and authority of Mr Kelly, a 68-year-old Marine combat veteran, retired four-star general and former Cabinet member.
The Trump White House remains full of strong personalities. National Security Adviser John Bolton is renowned as a brutal bureaucratic infighter. Economic adviser Larry Kudlow and trade adviser Peter Navarro are both skilled at pursuing their personal agendas via television appearances. Senior advisers Ivanka Trump and Jared Kushner enjoy blood ties with the President.
Mr Ayers may find it even harder to assert himself if he is appointed on an interim basis. Mr Trump and Mr Ayers have discussed the job for weeks, and Mr Ayers, who would like to return to his home state of Georgia by the end of the school year, has asked to serve in a brief transitional role, people familiar with the matter said. Mr Trump wants a two-year commitment.
On Saturday, Mr Trump also announced that he was nominating army chief of staff Mark Milley, a four-star general, as his next top military adviser - a new slap in the face for Pentagon chief James Mattis.
General Milley, who has served in Iraq and Afghanistan, would replace General Joseph Dunford as the military's next chairman of the Joint Chiefs of Staff.
Gen Dunford is scheduled to retire in October next year at the end of his second two-year term.
"I am thankful to both of these incredible men for their service to our country!" Mr Trump said on Twitter.
But in choosing 60-year-old Gen Milley, a graduate of Princeton University known for his combat command experience, Mr Trump went against the wishes of Mr Mattis, who reportedly favoured air force General David Goldfein. That choice would have been in keeping with a tradition of rotating the post among the services. Gen Dunford is a Marine Corps general. There has not been an air force officer in the chairman's post since 2005.
The Joint Chiefs of Staff is made up of the heads of the air force, army, marine corps, navy and national guard.
Gen Milley must be confirmed by the US Senate. He would take the position for a four-year term, after a new law was passed last year doubling the term length to better ensure continuity.
BLOOMBERG, AGENCE FRANCE-PRESSE