Opinion: Trump After Mattis

The Secretary of Defense worked to shield the world from President Trump’s worst impulses. But even he had his limits.

Jim Mattis, as secretary of defense, has done his best to preserve and defend the system of global alliances that the United States spent the last 70 years building and leading. In his resignation letter on Thursday, Mr. Mattis wrote that the United States was the “indispensable nation in the free world.” “Our strength as a nation,” he wrote, “is inextricably linked to the strength of our unique and comprehensive system of alliances and partnerships.”That’s apparently not the view held by President Trump, who ran for office calling for America to do less, calling for our allies to spend more and inviting rival nations to be more assertive.

Some people thought that once Mr. Trump was in office and had shouldered presidential responsibilities, he would adopt a less knee-jerk view of how best to keep the nation safe and the free world free.

Mr. Mattis, a respected and disciplined man, withstood Mr. Trump’s chaotic approach to governing longer than Rex Tillerson, the former secretary of state, and H.R. McMaster, the former national security adviser. He worked to prevent or blunt dangerous and impulsive presidential decisions, and he often made a difference.Mr. Mattis helped persuade Mr. Trump not to pull out of NATO and worked to assure Europe that the United States remained committed to a common defense of the continent.Mr. Mattis offered the same assurances to America’s allies in Asia, who are alarmed at an assertive China and unpredictable North Korea. Meanwhile, Mr. Trump, unconvinced of the value of the relationship with South Korea, threatened to withdraw forces there if Seoul didn’t bear a larger share of the basing costs.

During his saber-rattling phase with North Korea, Mr. Trump considered ordering the evacuation of military families from South Korea, which could have been interpreted by Pyongyang as a prelude to an American attack. According to CNN, Mr. Mattis worked to soften the order, which was never carried out.

When it came to other ill-considered presidential directives — a cruel ban on transgender troops and a self-aggrandizing military parade — Mr. Mattis quietly smothered the proposals with Pentagon bureaucracy.

Although he couldn’t prevent it, Mr. Mattis helped delay America’s abrogation of the Iran nuclear deal. He was also unable to prevent upending decades of Middle East policy by moving the American Embassy in Israel to Jerusalem without gaining any ground toward peace. In the end, it was Mr. Trump’s decision to immediately withdraw troops from Syria that pushed Jim Mattis over the edge.

On Wednesday, the president said he would withdraw all 2,000 American troops, a decision that was welcome news to Russia, Iran and Turkey. It was a bitter betrayal of groups like the Kurds, who have fought and died alongside American soldiers for more than a decade.Presidents, of course, have the authority to make such decisions. But presidents also traditionally plan out such decisions carefully and coordinate them with allies, particularly if fighting is underway.If the fellow in the next foxhole suddenly heads home, those fighters who remain are right to feel betrayed. In this case, in a telephone call with President Recep Tayyip Erdogan of Turkey, Mr. Trump said he would not object if Turkish forces invaded Syria and attacked Kurdish forces — including American allies — whom Ankara considers terrorists. Mr. Mattis could not get Mr. Trump to reverse course. And now, Mr. Trump is also considering a precipitous unilateral drawdown of forces in Afghanistan.

Presidents have tremendous power to make national security policy. But Congress also has a role to play, and it now needs to forcefully assert that responsibility.

Legislation requiring that the secretaries of state and defense have a say in the use of nuclear weapons is one good place to start. Another is to require congressional approval to leave NATO or other treaty obligations, like the Intermediate-Range Nuclear Forces Treaty.

More immediately, the Senate would be wise to hold out for a nominee for defense secretary who is more like Mr. Mattis than Mr. Trump.