But as the President prepares to once again review options this weekend for the US strategy in Afghanistan, he will arrive at Camp David to meet with his national security advisers with a new chief of staff at his side -- one who has commanded troops in Iraq and lost a son to the war in Afghanistan.
John Kelly has largely focused on instilling new order in a chaotic White House beset by internal division and controversies since he was tapped for the position late last month. But his sudden appointment also hurled the former four-star Marine Corps general into the decisive final stretch of a deeply divisive and often acrimonious internal White House debate over the Afghanistan war, putting him in a position to shape the debate at a critical juncture.
Now Kelly will step into the middle of that debate, carrying with him a 45-year military career and his personal experience as the father of a fallen Marine, 1st Lt. Robert Kelly, who was killed in Afghanistan in 2010.
Four retired Marine Corps generals who served with Kelly at different points in his career told CNN they believe Kelly will tackle the debate with a "no-nonsense" but very deliberative approach to help steer the President toward a decision on Afghanistan, ensuring in the process that Trump hears different sides of the debate.
"He's the right guy in this position right now," said retired Gen. John Allen, the former top US military commander in Afghanistan who has been friends with Kelly for four decades. "I think Kelly's going to be an honest broker."
The four generals all agreed that Kelly would focus on his role of chief of staff in helping to organize the debate to ensure the President gets the best information possible to make a decision, but said he would not shy away from sharing his own view if asked.
That was the case when Kelly served as legislative assistant to Gen. Michael Hagee, the Marine Corps commandant at the time.
"Most importantly, he told me what he thought, what he truly thought," Hagee said. "He was really a good partner and I could trust him that he would give me his opinion. I can tell you John will honestly always do that."
Gen. James Conway, Hagee's successor as Marine Corps commandant, put it more bluntly: "He's a big Boston Irishman. Don't ask John Kelly the question unless you can hear the answer."
The question is what Kelly's answer will be.
Kelly, who through a White House spokeswoman declined to be interviewed, has offered few public indications of his views on the war in Afghanistan, though Allen said Kelly has said he wants to see the US win in the country. Kelly's private comments preceded his White House tenure.
Kelly signaled as much in January 2016 when he addressed Gold Star families' hopes for the future of US military engagements.
"I think the one thing they would ask is that the cause for which their son or daughter fell be -- be carried through to -- to a successful end, whatever that means, as opposed to 'this is getting too costly,' or 'too much of a pain in the ass,' and 'let's just walk away from it.' Because that's when they start thinking it might have been not worth it," Kelly said in January 2016, shortly before his retirement from the military.
Asked about Kelly's role in the decision-making process, White House press secretary Sarah Huckabee Sanders said in a statement: "Gen. Kelly will make sure POTUS is properly staffed and informed so he can make the best decision for our country."
But to what extent will that advice be shaped by his status as a Gold Star father thrust into a position to shape the future of the war that claimed his son's life.
Kelly rarely discusses his son's death in public, but in the few comments he has offered on the topic Kelly has made clear that his son's death has given him a perspective shared by only a tiny sliver of Americans.
"I used to think that somehow I could begin to understand how bad the loss of a son or daughter would be,'' Kelly told the Boston Globe
a year after his son's death. "But you don't know what you don't know."
"The one huge revelation was I didn't have a clue how bad it hurt. I just had no idea. I was trying to empathize, trying to sympathize, trying to understand. And I thought like any person would. You kind of put it into terms like, 'well, I lost my mother, I lost my brother, it's kind of the same thing,'" Kelly said. "It ain't."
Kelly also described the loss of his son as a "physical sadness that doesn't got away."
In a speech he gave days after his son was killed after stepping on a landmine in Afghanistan in November 2010, Kelly noted that "we are in a life-and-death struggle, but not our whole country."
"One percent of Americans are touched by this war. Then there is a much smaller club of families who have given it all," Kelly said.
The four generals who spoke to CNN said they did not know how Kelly's son's death affected his views on the war in Afghanistan, but said the experience gave Kelly a better understanding of the true costs of war.
"Unlike the vast majority of the people in the White House or who have ever been in the White House in a permanent assignment, he understands what's at stake in not being successful in Afghanistan," said Allen, Kelly's longtime friend and the former US commander in Afghanistan.
Still, Allen said he believed Kelly would approach the war with a Marine's mindset and with a sense of patriotic duty.
"While yes, he has suffered -- he and Karen have suffered a terrible loss in that war -- I believe that seeing his duty as bringing the President the best advice possible he will do that even though he has lost one of his precious children in that war."
While Kelly is the only Cabinet-level official in the Trump administration to have lost a son to war, both Bannon and Vice President Mike Pence have a daughter and son, respectively, serving in the military.
Kelly's advice will also of course be shaped by his four decades in the military and his tours of duty commanding troops in Iraq, as well as the longstanding friendships -- more like a brotherhood -- he shares with Defense Secretary James Mattis and Gen. Joseph Dunford, the Chairman of the Joint Chiefs of Staff, two critical figures in the Afghanistan debate.
The four generals who spoke to CNN all pointed to the close and longstanding friendship between the three men, who have known each other throughout their military careers.
Dunford, at the time the assistant commandant of the Marine Corps, showed up at Kelly's doorstep to inform him of his son's death.
But whether he will side with Dunford and Mattis during the intense deliberations at Camp David is unclear.
While Kelly has said privately he wants to see the US emerge victorious in Afghanistan -- which could suggest he would be opposed to a significant drawdown or withdrawal from the country -- it's less than clear what victory would look like.
It may depend on where the goalposts lie -- and they have already moved as the President has raised fundamental questions about the US's role in Afghanistan and as some of his advisers have questioned longstanding US objectives like bolstering the country's centralized government
A senior administration official told CNN that at a late July meeting of the National Security Committee's Principals Committee the group of top advisers agreed to set "more realistic goals" for the US in Afghanistan, including casting aside the need to bolster Afghanistan's central government and aiming to degrade, but not destroy, the Taliban.
Regardless of the goals, Kelly's friends and former colleagues promised one thing: Kelly will be concerned with doing what's best for the country, and for the young servicemembers who would be put in harm's way.
"It's not about John Kelly," said Hagee, the former Marine Corps Commandant. "John will be concerned about only one thing and that's his country and the young men and women who serve his country."