President Donald Trump's interventions in US military policy, from reversing a Navy SEAL's demotion to withdrawal from Syria to a transgender ban, increasingly undermine Pentagon leadership, defence experts said Monday.
The firing on Sunday of Navy Secretary Richard Spencer, who challenged Trump's intervention in the SEAL commando's case, was the latest sign of the US military's struggle with Trump's off-the-cuff, highly political micromanagement.
Critics called it a sign of "disarray" that could send dangerous signals to troops on the ground and to US allies overseas that the Pentagon command structure can be overruled at any time by Trump, who wields authority as the US commander-in-chief.
"The senior military leadership is in a really difficult position," said Mara Karlin, Director of Strategic Studies at the School of Advanced International Studies at Johns Hopkins University.
"In terms of civil-military relations, what has been happening with the president is not a Democratic issue or a Republican issue, it's a dysfunctionality issue."
Last week Trump defied the Pentagon leadership by rejecting their plans to demote and force Navy commando Edward Gallagher out of the elite SEALs after his conviction for having posed for a picture next to the body of a dead Islamic State fighter.
Trump was drawn to supporting Gallagher after Fox News made his case a conservative political cause early this year.
Navy officials feared that letting off Gallagher, who avoided conviction on murdering a prisoner in Iraq, would signal to other SEALs that they can get away with crimes.
"This was an outrageous, irresponsible interference by President Trump in the military justice system," Democratic Senator Jack Reed said Monday.
"It signals to people that they can operate outside the rule of law and the Geneva Convention."
But it was only the latest intervention by Trump in military affairs.
Earlier this year, while the Pentagon was assessing bids for a $10 billion cloud computing contract, Trump weighed in against Amazon, which owns the Washington Post, a frequent critic of his administration.
A new book on former Defence Secretary James Mattis, written by his speechwriter Guy Snodgrass, contends that Trump told Mattis to "screw Amazon" out of the contract, which was awarded in October to Microsoft.
He has attacked key alliances, including NATO, and arms control treaties, and, against Pentagon advice, he avidly pursued a detente with North Korea while criticising ally South Korea.
Last year he reversed, via Twitter, a Pentagon policy accommodating transgender soldiers.
He also pressured the Defence Department to hold a massive parade of military hardware; and in December unilaterally announced the withdrawal for US troops from Syria and Afghanistan, a move that led to Mattis's resignation.
Many, if not most of those moves, analysts say, were driven by domestic political considerations rather than strategic rationale, and all were opposed by the Pentagon leadership.
"It's important that we don't see these as discreet. There is one example after another," said Karlin.
Peter Feaver, a specialist in civil-military relations at Duke University, says disagreements and tensions between the White House and the Department of Defence are normal.
But with Trump it is extreme, he said, with the president dismissing his military advisors "out of hand."
It's a big problem when "the boss is viewed as mercurial and hard to brief," Feaver said.
"Most administrations would try to hide this stuff... Instead, this president does things in public."
The cost to both sides is a loss of trust, effectiveness and the ability to retain top talent.
It also leads US partners and adversaries to questions decision-making in the Pentagon.
"Allies need to trust that they can cut a deal with whoever they are dealing with on Trump's team, and that that will stand for what the president will finally do," Feaver said.
"That's just harder to do in this administration, because the president keeps overruling his own team."
Caitlin Talmadge, an associate professor at Georgetown University, said via Twitter that Trump firing a civilian political appointee like Spencer is not uncommon.
His motivation is the problem -- "Trump undermines military justice system for political advantage," she said, and he "lionizes those he believes violate norms & laws of war."
Spencer's firing, she added, illustrates the "lack of well-coordinated & institutionalised... decision-making processes, which has all sorts of actual bad policy consequences."