WASHINGTON — Former Defense Secretary Jim Mattis, breaking months of public silence on President Trump since resigning in protest in December 2018, on Wednesday offered a withering critique of the president’s leadership amid growing protests across the country.
“Donald Trump is the first president in my lifetime who does not try to unite the American people — does not even pretend to try,” Mr. Mattis wrote in a statement issued late Wednesday. “Instead he tries to divide us. We are witnessing the consequences of three years of this deliberate effort. We are witnessing the consequences of three years without mature leadership.”
Mr. Mattis, a retired four-star Marine Corps general, also criticized comments by the current defense secretary, Mark T. Esper, who in recent days has described protest sites across the nation as a “battle space” to be cleared.
“We must reject any thinking of our cities as a ‘battle space’ that our uniformed military is called upon to ‘dominate,’” Mr. Mattis wrote. “At home, we should use our military only when requested to do so, on very rare occasions, by state governors. Militarizing our response, as we witnessed in Washington, D.C., sets up a conflict — a false conflict — between the military and civilian society.”
Mr. Trump fired back on Twitter. “Probably the only thing Barack Obama & I have in common is that we both had the honor of firing Jim Mattis, the world’s most overrated General,” he said, although Mr. Mattis quit.
The president added: “His primary strength was not military, but rather personal public relations. I gave him a new life, things to do, and battles to win, but he seldom ‘brought home the bacon’. I didn’t like his ‘leadership’ style or much else about him, and many others agree. Glad he is gone!”
Mr. Mattis’s condemnation carries huge weight in military circles, where he remains highly influential. In the insular world of Marines, he has an almost cultlike status. But that influence extends far beyond just the military to include much of the national security establishment, members of Congress, foreign dignitaries and defense contractors.
For instance, at the Reagan National Defense Forum in Simi Valley, Calif., last December, Mr. Mattis, gliding through a reception of influential national security thinkers from government and the private sector, was stopped constantly by people who wanted to shake his hand and take photos with him. A crowd of people trailed him as he made his way through the hall, amid excited murmurs of, “Hey, Mattis is here.”
But his refusal to publicly denounce Mr. Trump since his resignation — over the president’s decision to withdraw troops from Syria — earned him criticism even from some longtime admirers. He repeatedly told reporters who sought comment from him or engaged him during a tour of his best-selling book that he did not want to criticize a sitting commander in chief.
But the events of Monday night, in which Mr. Trump put peaceful American protesters squarely in the cross hairs of the American military that is sworn to protect the Constitution, was a step too far for Mr. Mattis, people who have spoken to him say.
“When I joined the military, some 50 years ago, I swore an oath to support and defend the Constitution,” Mr. Mattis wrote. “Never did I dream that troops taking that same oath would be ordered under any circumstance to violate the constitutional rights of their fellow citizens — much less to provide a bizarre photo op for the elected commander in chief, with military leadership standing alongside.”
During a long and tense Monday night, protesters in Lafayette Square near the White House were forcibly removed so Mr. Trump could walk to a nearby church — with the Mr. Esper and the chairman of the Joint Chiefs of Staff, Gen. Mark A. Milley — for a photo op.
“We must not be distracted by a small number of lawbreakers,” Mr. Mattis said. “The protests are defined by tens of thousands of people of conscience who are insisting that we live up to our values — our values as people and our values as a nation.”
Citing James Madison’s Federalist Paper 14, Mr. Mattis said: “We do not need to militarize our response to protests. We need to unite around a common purpose. And it starts by guaranteeing that all of us are equal before the law.”
Reached by phone at his home in Washington State on Wednesday night, Mr. Mattis declined to comment.
In Mr. Mattis’s early days as defense secretary, he often ate dinner with the president in the White House residence. Over hamburgers, and with the help of briefing folders, Mr. Mattis explained to Mr. Trump key points about the United States’ relationships with allies — a bedrock principle for the former general turned secretary.
But Mr. Mattis also quietly slow-walked many of Mr. Trump’s proposals, including banning transgender troops, starting a Space Force and putting on a costly military parade in the capital. In each case, he went through the motions of acquiescing to the White House — and then buried the plans in Defense Department red tape.
By late 2018, the relationship between Mr. Mattis and Mr. Trump had deteriorated badly. The widely accepted narrative that Mr. Mattis was the adult in the room, an anchor of reason in a stormy White House, came to annoy the president.
Even as his influence with Mr. Trump waned, however, Mr. Mattis repeatedly told friends and aides that he viewed his responsibility to protect the United States’ 1.3 million active-duty troops as worth the concessions necessary as defense secretary to a mercurial president.
But Mr. Trump’s abrupt decision in late December 2018 to withdraw roughly 2,000 American troops from eastern Syria without consulting allies was a step too far for Mr. Mattis, and he resigned. Mr. Mattis’s letter of resignation condemned Mr. Trump’s approach to the world as destructive to American influence and power.
In his statement on Wednesday, Mr. Mattis sounded a call to arms of a different sort than have resounded in the streets near the White House, and across the country.
“We know that we are better than the abuse of executive authority that we witnessed in Lafayette Square,” Mr. Mattis said. “We must reject and hold accountable those in office who would make a mockery of our Constitution.”