President Trump has decided to remove H.R. McMaster as his national security adviser and is actively discussing potential replacements, according to five people with knowledge of the plans, preparing to deliver yet another jolt to the senior ranks of his administration.

Trump is now comfortable with ousting McMaster, with whom he never personally gelled, but is willing to take time executing the move because he wants to ensure both that the three-star Army general is not humiliated and that there is a strong successor lined up, these people said.

The turbulence is part of a broader potential shake-up under consideration by Trump that is likely to include senior officials at the White House, where staffers are gripped by fear and un­certainty as they await the next move from an impulsive president who enjoys stoking conflict.

For all of the evident disorder, Trump feels emboldened, advisers said — buoyed by what he views as triumphant decisions last week to impose tariffs on steel and aluminum and to agree to meet with North Korean leader Kim Jong Un. The president is enjoying the process of assessing his team and making changes, tightening his inner circle to those he considers survivors and who respect his unconventional style, one senior White House official said.

And on Thursday, Trump signaled that more personnel moves were likely. “There will always be change,” the president told reporters. “And I think you want to see change. I want to also see different ideas.”

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This portrait of the Trump administration in turmoil is based on interviews with 19 presidential advisers and administration officials, many of whom spoke on the condition of anonymity to offer candid perspectives.

The mood inside the White House in recent days has verged on mania, as Trump increasingly keeps his own counsel and senior aides struggle to determine the gradations between rumor and truth. At times, they say, they are anxious and nervous, wondering what each new headline may mean for them personally.

Many aides were particularly unsettled by the firing of the president’s longtime personal aide, John McEntee, who was marched out of the White House on Tuesday after his security clearance was abruptly revoked.

“Everybody fears the perp walk,” one senior White House official said. “If it could happen to Johnny, the president’s body guy, it could happen to anybody.” 

National Security Adviser H.R. McMaster speaks during a White House press briefing last year. (Jabin Botsford/The Washington Post)

Trump recently told White House Chief of Staff John F. Kelly that he wants McMaster out and asked for help weighing replacement options, according to two people familiar with their conversations. The president has complained that McMaster is too rigid and that his briefings go on too long and seem irrelevant.

Several candidates have emerged as possible McMaster replacements, including John Bolton, a former U.S. ambassador to the United Nations, and Keith Kellogg, the chief of staff of the National Security Council.

Kellogg travels with Trump on many domestic trips, in part because the president likes his company and thinks he is fun. Bolton has met with Trump several times and often agrees with the president’s instincts. Trump also thinks Bolton, who regularly praises the president on Fox News Channel, is good on television.

Some in the White House have been reluctant to oust McMaster from his national security perch until he has a promotion to four-star rank or other comfortable landing spot. They are eager to show that someone can serve in the Trump administration without suffering severe damage to their reputation.

McMaster is not the only senior official on thin ice with the president. Veterans Affairs Secretary David Shulkin has attracted Trump’s ire for his spending decisions as well as for general disorder in the senior leadership of his agency.

Others considered at risk for being fired or reprimanded include Housing and Urban Development Secretary Ben Carson, who has generated bad headlines for ordering a $31,000 dining room set for his office; Environmental Protection Agency Administrator Scott Pruitt, who has been under fire for his first-class travel at taxpayer expense; and Interior Secretary Ryan Zinke, whose agency spent $139,000 to renovate his office doors.

Meanwhile, Education Secretary Betsy DeVos drew attention this week when she stumbled through a pair of high-profile television interviews. Kelly watched DeVos’s sit-down with Lesley Stahl of CBS’s “60 Minutes” with frustration and complained about the secretary’s apparent lack of preparation, officials said. Other Trump advisers mocked DeVos’s shaky appearance with Savannah Guthrie on NBC’s “Today” show.

Kelly’s own ouster has been widely speculated for weeks. But two top officials said Trump on Thursday morning expressed disbelief to Vice President Pence, senior advisers and Kelly himself that Kelly’s name was surfacing on media watch lists because his job is secure. Trump and Kelly then laughed about it, the officials said.

The widespread uncertainty has created power vacuums that could play to the advantage of some administration aides.

Pompeo, who carefully cultivated a personal relationship with the president, had positioned himself as the heir apparent to Tillerson, whom Trump had long disliked.

Similarly, Pruitt has made no secret inside the West Wing of his ambition to become attorney general should Trump decide to fire Jeff Sessions, who he frequently derides for his decision to recuse himself from the investigation of Russian interference in the 2016 election.

White House officials have grown agitated that Pruitt and his allies are privately pushing for the EPA chief to replace Sessions, a job Pruitt has told people he wants. On Wednesday night, Kelly called Pruitt and told him the president was happy with his performance at EPA and that he did not need to worry about the Justice Department, according to two people familiar with the conversation.

With Hope Hicks resigning her post as communications director, the internal jockeying to replace her has been especially intense between Mercedes Schlapp, who oversees the White House’s long-term communications planning, and Tony Sayegh, Treasury Secretary Steven Mnuchin’s top communications adviser.

Trump enjoys watching his subordinates compete for his approval. Many of the rumors are fueled by Trump himself because he complains to aides and friends about other staffers, or muses about who might make good replacements.

“I like conflict. I like having two people with different points of view,” Trump said last week, rapping his fists toward one another to simulate a clash. “I like watching it, I like seeing it, and I think it’s the best way to go.” 

Shulkin, meanwhile, is facing mounting trouble after The Washington Post first reported that he and his wife took a sightseeing-filled trip to Europe on taxpayer funds, including watching tennis at Wimbledon. Shulkin is now facing an insurrection at his own agency, with tensions so high that an armed guard stands outside his office.

Another episode haunting Shulkin was a trip to the Invictus Games in Canada last September with first lady Melania Trump’s entourage. Shulkin fought with East Wing aides over his request that his wife accompany him on the trip because he was eager for her to meet Prince Harry of Wales, who founded the games, according to multiple officials familiar with the dispute.

The first lady’s office explained there was not room on the plane for Shulkin’s wife, and officials said the secretary was unpleasant during the trip.

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Shulkin said in an email sent by a spokeswoman: “These allegations are simply untrue. I was honored to attend the Invictus Games with the First Lady and understood fully when I was told that there wasn’t any more room for guests to attend.”

A leading contender to replace Shulkin is Pete Hegseth, an Iraq War veteran and Fox News personality who is a conservative voice on veterans policy, officials said.

White House officials said there are several reasons Trump has not axed Cabinet members with whom he has grown disenchanted: the absence of consensus picks to replace them; concern that their nominated successors may not get confirmed in the divided Senate; and reluctance to pick allied senators or House members for fear of losing Republican seats in special elections, as happened last year in Alabama.

Also, Trump has sometimes expressed confusion about what agencies and secretaries are in charge of what duties, a senior administration official said. For example, this official said, he has complained to Pruitt about regulatory processes for construction projects, although the EPA is not in charge of the regulations.

Amid the disarray, White House staff are training Cabinet secretaries and their staffs on ethics rules and discussing new processes to prevent mistakes. William J. McGinley, who runs the White House Office of Cabinet Affairs, and Stefan C. Passantino, a deputy White House counsel, have met individually and in groups with Carson, Pruitt, Shulkin, Zinke and other Cabinet secretaries to impress upon them the importance of changing behavior.

Simply following the letter of the law is not enough, administration officials said. Trump and Kelly demand that their Cabinet secretaries be mindful of political optics and the bad headlines that come with misbehavior.

“Even if the legal guys sign off on it,” one official said, “you still step back and say, ‘Does this make sense optically?’ ”

Greg Jaffe contributed to this report.