“Based upon his outstanding service to the Country and his demonstrated ability to lead, President Trump intends to nominate Patrick M. Shanahan to be the Secretary of Defense,” White House spokeswoman Sarah Sanders said in a statement on Twitter.

The move brings greater stability to Trump’s national security team. Sanders cited Shanahan’s leadership in recent months — he’s the longest serving acting Pentagon chief in U.S. history — as evidence that he’s “beyond qualified to lead the Department of Defense, and he will continue to do an excellent job.”

Shanahan, 56, has been acting defense secretary since Mattis stepped down over Trump’s abrupt announcement that he was withdrawing all 2,000 U.S. troops from Syria. He’s since proven his loyalty, backing Trump’s efforts to tap Pentagon funding for a border wall over bipartisan congressional opposition and working to scale back, though not eliminate, American forces in Syria.

When Shanahan assumed command of American armed forces as acting secretary, he said in a statement that he looked “forward to working with President Trump to carry out his vision alongside strong leaders.” And when Trump disparaged Mattis at a cabinet meeting in early January — scoffing “what’s he done for me?” — Shanahan was at the president’s side.

In an interview in February, Shanahan brushed aside criticism that he was auditioning for the role of defense secretary through his vocal enthusiasm for the president’s initiatives, saying the approach could be summed up by the acronym GSD — “get stuff done.”

‘Getting Stuff Done’

“Let’s not worry about whether he’s a ‘yes man’ or a ‘no man’ but whether he’s a ‘can-do’ man,” Shanahan said of himself. “I just spend all my time getting stuff done.”

In December, Trump praised Shanahan in a tweet, saying he had a “long list of accomplishments while serving as Deputy, & previously Boeing.”

Shanahan, an engineer by training, rose to senior vice president at Chicago-based Boeing. He had 30 years of experience at the company across its key military, space and commercial aviation businesses but made his mark in 2007, when he was assigned to help fix cascading development issues that had left the 787 Dreamliner years behind schedule.

He has recused himself from decisions on Boeing contracts, and on April 25 was cleared by the Pentagon’s inspector general of allegations by an advocacy group that he had showed favoritism toward his former employer.

Rejected Allegations

“We determined that Mr. Shanahan fully complied with his ethics agreements and his ethical obligations regarding Boeing and its competitors,” the inspector general wrote in a 36-page report released on April 25. The report rejected allegations that he offered praise of Boeing and put-downs of rival Lockheed Martin Corp. as well as concern about the appearances raised by Air Force Secretary Heather Wilson.

Senators are likely to press Shanahan further on the difficulty of sidestepping such appearances of conflict because Lockheed, the No. 1 U.S. defense contractor, and Boeing, which is No. 2, loom so large in Defense Department budgeting and decision-making.

While acknowledging that the inspector general’s report cleared him of wrongdoing, Senator Jack Reed, the panel’s top Democrat, said in a statement that the report “also shows the wide swath of national security matters that Acting Secretary Shanahan is barred from, which strikes me as something the Senate needs to consider.”

‘My Generals’

Unlike Mattis — whom Trump described as one of “my generals” — Shanahan never served in the military. But defense secretaries generally have come to the job from civilian life. Most recently, Ashton Carter, who was defense secretary under President Barack Obama, was never in the military, although he had a lengthy resume in civilian defense posts and related academic positions.

Mattis was widely seen as a moderating force against Trump’s hostility toward traditional American alliances and overseas military commitments.

The announcement of his departure stunned congressional leaders of both parties, many of whom had openly criticized Trump’s reversal of longstanding policy on Syria.

While Trump’s initial Syria announcement in December drew bipartisan criticism and protests from allies, Shanahan said in the interview that decision-making among the president’s top aides has been exceptionally smooth and “effortless.”

He cited his working relationship with cabinet counterparts including Secretary of State Michael Pompeo and National Security Adviser John Bolton.