This is not the image Army officials had wanted.
While tanks, armored troop carriers and artillery systems pour into Washington for the Army’s 250th birthday celebration, National Guard troops from the Army’s 79th Infantry Brigade Combat Team, supplemented by active-duty Marines, have been deployed to the streets of Los Angeles.
It is a juxtaposition that has military officials and experts concerned.
Several current and former Army officials said the military parade and other festivities on Saturday — which is also President Trump’s 79th birthday — could make it appear as if the military is celebrating a crackdown on Americans.
“The unfortunate coincidence of the parade and federalizing the California National Guard will feel ominous,” said Kori Schake, a former defense official in the George W. Bush administration who directs foreign and defense policy studies at the American Enterprise Institute.
Dr. Schake initially did not consider the parade much of a problem but is now concerned about “the rapid escalation by the administration” in Los Angeles.
The two scenes combined “erode trust in the military at a time when the military should be a symbol of national unity,” said Max Rose, a former Democratic congressman and an Army veteran.
“They are deploying the National Guard in direct contradiction to what state and local authorities requested, and at the same time there’s this massive parade with a display more fitting for Russia and North Korea,” he said.
It was unclear exactly what grounds Mr. Trump and the Defense Department are using to deploy active-duty Marines to an American city. The Posse Comitatus Act generally prohibits active-duty forces from providing domestic law enforcement unless the president invokes the little-used Insurrection Act.
But in his order federalizing California’s National Guard, Mr. Trump cited Title 10 of the United States Code, which lays out the legal basis for the use of U.S. military forces.
Mr. Trump wanted to invoke the Insurrection Act to use active-duty military troops against Black Lives Matter protesters during his first term. But his defense secretary, Mark T. Esper, and the chairman of the Joint Chiefs of Staff, Gen. Mark A. Milley, both opposed the move, and Mr. Trump held back.
The moment proved to be a breaking point between Mr. Trump and the Pentagon. The president eventually fired Mr. Esper, and he has suggested General Milley should be executed.
This time, Mr. Trump’s defense secretary, Pete Hegseth, has cheered him on.
Within minutes of Mr. Trump’s order on Sunday deploying the first 2,000 National Guard troops to join the scattered immigration protests in Los Angeles, Mr. Hegseth threatened to deploy active-duty Marines from, he said, Camp Pendleton. (The Marines who deployed on Monday night were from Twentynine Palms, a base about 150 miles east of Los Angeles, but Mr. Hegseth continued to say Camp Pendleton, which is about 100 miles south of the city).
By Monday night, 700 Marines and another 2,000 National Guard troops had been activated for largely peaceful protests that have, so far, done relatively little damage to buildings or businesses. And on Tuesday, Mr. Trump said that anybody protesting the parade in Washington would “be met with very big force.”
Mr. Hegseth defended the deployments in congressional testimony on Tuesday, saying, “We ought to be able to enforce immigration law in this country.”
Mr. Hegseth’s term has been defined by his amplification of the president. He has enthusiastically backed the Army’s plans to hold a rare military parade, in which 150 military vehicles, including 28 tanks and 28 heavy armored troop carriers, will roll down the streets of the capital, granting Mr. Trump the celebration he has wanted for years.
Democratic lawmakers and some military veterans expressed fear that Mr. Hegseth, himself a National Guard veteran who was deployed against Black Lives Matters protesters in 2020, was taking the military where it has traditionally least wanted to be: into the middle of a political battle.
“The president’s decision to call the National Guard troops to Los Angeles was premature, and the decision to deploy active-duty Marines as well is downright escalatory,” Representative Betty McCollum, Democrat of Minnesota, said at a House committee hearing on Tuesday as lawmakers grilled Mr. Hegseth. “Active-duty military has absolutely no role in domestic law enforcement, and they are not trained for those missions.”
One defense official said that Pentagon lawyers believe they have found some leeway in the Title 10 provision that Mr. Trump used to order National Guard troops to Los Angeles against the wishes of California’s governor, Gavin Newsom.
The Marines will help protect federal property and federal agents in Los Angeles, the U.S. military’s Northern Command said in a statement.
But unlike law enforcement officers or even National Guard troops, who practice controlling crowds during protests, active-duty troops are trained to respond to threats quickly and with lethal force.
“I do not take the position that invoking the Insurrection Act is necessary at this point; the facts on the ground don’t justify it,” said Daniel Maurer, a retired Army lieutenant colonel who served as a judge advocate general. “It’s almost like a show of force to the MAGA base, if you will.” Mr. Maurer is now a law professor at Ohio Northern University.
Concerns about the parade surfaced even before the Trump administration deployed troops to Los Angeles.
“The challenge of the parade all along has been how to celebrate the military’s 250-year contribution to the Republic while avoiding the politicization that comes from our current polarized partisan environment,” said Peter Feaver, a political science professor at Duke University who has studied the military for decades. “That challenge is considerably harder when some units are seen parading at the same time other units are seen policing a public protest.”
One Army official, speaking on the condition of anonymity to avoid alienating Mr. Trump, said she would be leaving town during the events.
Janessa Goldbeck, a Marine Corps veteran who is now a senior adviser at the veterans advocacy group VoteVets, said she was worried that the Marines and the National Guard were being led into a political maelstrom that could damage their relations with the American public.
“Young men and women who sign up to serve, to volunteer in their communities, to respond to wildfires and other natural disasters,” she said, “are now being put in this very dicey position politically.”
Eric Schmitt contributed reporting.