OK, let’s combine today’s two most obnoxious Washington-speak clichés into one ugly mashup:

Trump has thrown the last adult in the room under the bus.

“Mattis Exit Paves Way for Global Chaos” was the sober CNN top headline during the hours following the announcement Thursday of the defense secretary’s resignation.

The end is near. If the Church of Mammon heard confessions, Washingtonians would be queued out along Constitution Avenue waiting to be shriven and wondering if Mammon even cared if they were heartily sorry.

James Mattis will join Nikki Haley on the outside of the Trump Administration, where Bill Kristol has been wanting them to be, the better to be available on Kristol’s dream team of prospective NeverTrump candidates for president in 2020.

Sixteen months ago, Mattis was riding high within a Trump Administration with a different makeup. In August 2017, he joined other top officials in getting the president to postpone carrying out his campaign promise to withdraw U.S. troops from Afghanistan.

“The game plan agreed upon at Camp David,” said a report in RealClearDefense, “was a triumph for Mattis and [then-national security adviser Lt. Gen. H.R.] McMaster, said retired Army Lt. Gen. Thomas Spoehr, a military analyst. The two worked hand-in-hand with Secretary of State Rex Tillerson and Vice President Mike Pence.”

McMaster had arranged for Pence to cut short an official visit to Latin America, becoming a diplomatic no-show in key capitals in order to join Tillerson and Mattis in strong-arming Trump into postponing the Afghan withdrawal. Four-star General John Kelly, who recently had become White House chief of staff, also was one of the advisers urging Trump to keep American soldiers in Afghanistan.

By caving to a national security adviser he said “looks like a beer salesman” and a chief diplomat he now recalls as “dumb as a rock,” Trump won “Strange New Respect” in The Swamp. Senator John McCain (R-Ariz.) praised Trump’s decision. Across the aisle, Senator Tim Kaine (D-Va.) said it was a positive step inasmuch as it went in the direction McCain wanted to go.

Today Trump is behaving with the shrewdness and self-awareness of a civilian commander-in-chief who knows, with Clemenceau, that war is too important to be left to the generals. Trump recognizes too, with another French leader, Charles de Gaulle, that the cemeteries are full of indispensable men.

Mattis, it must not be denied, is a patriot and a man of learning and intellectual discipline. But he’s not infallible. Military and civilian leaders with comparable qualities have disagreed and will disagree with him.

As the Trump Administration implements the president’s promises to get troops out of Syria and Afghanistan, the wisdom of one of the great Cold War scholar-generals should be a major policy guide.

Army Lt. General William E. Odom (1932-2008) was one of the bravest and most brilliant military intelligence officers of his generation. An expert on the Soviet Union with a doctorate in political science from Columbia, he was President Ronald Reagan’s director of the National Security Agency, the electronic spying outfit. A thinking man as well as a fighting man, he was one of the architects of what Margaret Thatcher remembered as Reagan’s winning the Cold War “without firing a shot.”

Odom taught at Yale for two decades following his retirement, and his warnings about U.S. military deployments in the Middle East were wise and prophetic.

A large body of Odom’s writings about the U.S. invasions of Iraq and Afghanistan and related Middle East security issues is collected on the website of the Harvard Nieman Fellows program.

In August 2005, Odom wrote “What’s Wrong with Cutting and Running?”—an article that made him persona non grata in the George W. Bush administration.

“If I were a journalist,” Odom began, “I would list all the arguments that you hear against pulling U.S. troops out of Iraq, the horrible things that people say would happen, and then ask: Aren’t they happening already? Would a pullout really make things worse? Maybe it would make things better.”

Odom went on to list the arguments—many of the same arguments Trump heard applied to Afghanistan from Mattis and McCain and McMaster and Kelly and Tillerson and Pence 16 months ago; and the same as we are hearing from almost everywhere today.

Here are a few notes from the familiar refrain, with the essence of Odom’s responses:

We would leave behind a civil war.

“Iraqis are already fighting Iraqis. Insurgents have killed far more Iraqis than Americans. That’s civil war.”

We would lose credibility on the world stage.

“A hyperpower need not worry about credibility. That’s one of the great advantages of being a hyperpower: When we have made a big strategic mistake, we can reverse it. And it may even enhance our credibility. Staying there damages our credibility more than leaving.”

It would embolden the insurgency and cripple the move toward democracy.

“The U.S. will not leave behind a liberal, constitutional democracy in Iraq no matter how long it stays. Holding elections is easy. It is impossible to make it a constitutional democracy in a hurry.”

The scholar, soldier and strategist whose words our government needs to consider most of all today is the late William Odom, who said presciently:

“Those who fear leaving a mess are actually helping make things worse while preventing a new strategic approach with some promise of success.”

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