The headline says it all:

The Revenge of Jim Mattis

The op-ed then continued.

In his statement to the Atlantic, Mr Mattis denounced in particular Mr Trump’s threat this week to order the military to restore order amid riots in US cities. He said this threatens the Constitution, which is overwrought given that George HW Bush and other Presidents have done this. Mr Mattis also undersold the significant harm that riots have done in many cities (see nearby).

This is a misreading of history that, from a man who has styled himself a student of it, can only be taken as cynical. Mattis is ignoring the use of the military to restore order amid riots by Presidents Eisenhower and Bush the Elder, entirely constitutional uses.

And

Donald Trump is the first president in my lifetime who does not try to unite the American people—does not even pretend to try. 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.

Mattis ignores even recent history, about which he’s mischaracterized the divisiveness extant. He carefully ignores the utter contempt with which Progressive-Democratic Party Presidential candidate Hillary Clinton and the man she hoped to replace, Barack Obama, held millions of Americans: bitter Bible- and gun-clinging denizens of flyover country, irredeemable and deplorable. He carefully ignores the NLMSM’s so-unifying practice of calling Tea Partiers “tea baggers,” then- (as now) House Speaker Nancy Pelosi’s (D, CA) calling them astro-turfers. He carefully ignores current Progressive-Democratic Party Presidential nominee Joe Biden’s contempt for black Americans: if they’re confused about whether to vote for Biden, they’re not black. (Biden since has extended that Progressive-Democratic contempt to 10-15 per cent of Americans being just not very good people, but that post-dates Mattis’ diatribe.)

Mattis also carefully ignores Trump’s work toward unification—prison reform; jobs for blacks, Hispanics, women; funding for Historically Black Colleges; on and on.

These are breathtaking…failures…by that historian.

And this letter from an erstwhile Presidential lawyer:

Jim:
I slept on your statement and woke up appalled and upset. You lost me. Never dreamed you would let a bunch of hack politicians use your good name and reputation—earned with the blood and guts of young Marines. You did what you said you would—engage in this discourse. Marines keep their word.
The phony protesters near Lafayette park were not peaceful and are not real. They are terrorists using idle hate filled students to burn and destroy. They were abusing and disrespecting the police when the police were preparing the area for the 1900 curfew. Jim, this is the new nihilism. See Dan Henninger in WSJ today. Marines support the police in harms way.
Did you forget that President Bush used active duty Marines to quell the riots in LA? President Trump has countless cities and some snowflake governors and mayors wetting themselves in the use force to protect innocent lives and property. The AG of Massachusetts thinks burning property is good protest.
Three more policemen were stabbed and shot in NYC last night.
Think about it. Should he be upset about the obvious failure of leadership? Where are you Jim?
Marines go to the fight.
No one divided this country more than Obama. He abandoned our black brothers and sisters. He gave guns to the cartels. He apologized for our precious sacrifice and generosity overseas.
President Trump has done more to help our minority brothers and sisters in the three years than anyone in the last fifty. Ask the black pastors. Ask the leaders of the black colleges and universities. He got them funded. Ask them about the prison reform which ended the draconian sentences imposed on young black men by the laws enacted by Biden and his hacks. You need to bone up on your homework and stop listening to Uncle Leon.
I understand, you had to stick to the assigned narrative which did not include three years of corrupt investigations and evidence to destroy this President, his office, and his lawful free election. Nancy has no tolerance for dissent in the ranks—including those with stars.
You said nothing of the ugly, hate filled, disgraceful comments of Pelosi, Schumer, Perez and other Democrat hacks defaming the President and his office. You said nothing of the unlawful sanctuary cities and the unlawful release of hoodlums. You said nothing of the resistance movement to paralyze our courts and our government operations. You said nothing of the obstruction and subversion of our immigration laws. You said nothing of MS-13 killers and the drug cartels who own huge sections of our major cities. Jim, do you think that hateful rhetoric and those corrupt actions were inspiring and unifying? Do you think the DI’s at Parr’s Island would find such behavior as unifying?
Maybe, your problem, is a lot deeper. Perhaps you ought to explain how and why you (and John Allen), as CG Central Command, did not engage and take out Iranian Major General Soleimani who roamed the Middle East and wreaked havoc and death of American boys with his infamous IEDs?
Why did it take President Trump to have the instinct and balls to take him out (of course over the objection the geniuses in the Pentagon)?
Looks like the Persian mullahs were a one horse sleigh and Trump nailed the horse….forever. It has been quiet ever since. Perhaps, your anger is borne of embarrassment for your own failure as the leader of Central command. Did you applaud when the President recognized the central problem in the middle east? Did you applaud the President when he wanted to save American lives by bringing them home in one piece?
John M Dowd

The Wall Street Journal says in the first link above,

Mr Mattis, the former four-star Marine General, is a man of accomplishment and dedication to country.

In his book, Call Sign Chaos, however, Mattis wrote:

I don’t write about sitting presidents.

General Mattis was, indeed, a man of accomplishment. It seems, though, that Mister Mattis’ word is less accomplished. As is his level of rationality.