“A Sacred Oath,” the just-released book by President Trump’s former defense secretary, Mark Esper, is a pretentious and provokingly self-righteous canon of the Never-Trump movement. Mr. Esper, now out of office, served a total of three years in the Trump administration almost equally divided between the positions of secretary of the Army and secretary of defense.

These are non-political offices, but Mr. Esper ingratiated himself sufficiently with the Trump administration that as a West Point graduate and veteran of the illustrious 82^nd Airborne and 101^st Airborne divisions and with a defense industry background, he was a natural choice as secretary of the Army.

In more than two years in that position, he had a full opportunity to observe closely the policies and character of the president whom he served. If he had had conscientious problems with President Trump, he should not have accepted promotion to the high office of secretary of defense, which has for the last 75 years been held by some of the most prominent American public figures, including General George C Marshall, Robert A. Lovett, Clark M. Clifford, Caspar Weinberger, Frank Carlucci, Dick Cheney, Robert Gates, and General James Mathis, whom he succeeded.

Mr. Esper was perfectly aware of the differences of opinion that General Mathis had with Mr. Trump, but was happy to replace him at the Pentagon anyway. Mr. Esper was thus familiar with the views of the president in all military-related matters, but instead of retiring with Secretary Mattis, he eagerly took his place in order to continue to subvert and undermine the president’s policies, in evident concert with the egregious chairman of the Joint Chiefs of Staff, General Mark Milley, until Mr. Trump fired him for cause.

Mr. Esper and General Milley both joined in the famous walk from the White House to St. John’s Church across Lafayette Park, “the presidents’ church” since the time of James Madison, which would have been torched by the “peaceful protesters” of the summer of 2020 if the president and the attorney general had not facilitated the extinction of the fire that the anti-Trump arsonists set there.

Mr. Esper’s evident plan was to use his office to obstruct as much as possible the re-election of the president who did him the honor of appointing him to that office. It is also true that as both secretary of the Army and of defense he bears considerable responsibility for administering the great increase in the defense budget that Mr. Trump secured in ways that failed to counter the Russian and Chinese initiatives in hypersonic weapons, and failed to provide adequate protection for the Nimitz class aircraft carriers that are the core of the projection of American forces overseas.

Mr. Esper’s memoir is admittedly an agile effort from an anti-Trump Republican with no electoral history to take a leading position among the anti-Trump Republicans by proudly stating that he agreed with much of Mr. Trump’s policy but felt a patriotic mission to betray and help to defeat the president whom he served. The sacred oath referred to in the title of his monumentally self-serving memoir is the tediously repeated pledge not to do anything “illegal, immoral, or unethical.”

General Mattis and others in the Trump administration, as in preceding presidencies, implicitly considered it unethical to continue in high office when in fundamental disagreement with the president on important issues. Mr. Esper followed a wide arc in four years from being a well-paid lobbyist of the armaments industry (Aerospace Industries Association and Raytheon), through his senior government service to concluding that Mr. Trump is “an unprincipled person who, given his self-interest, should not be in the position of public service.”

This Damascene revelation must surely have come to him relatively early in his close official relationship with Mr. Trump and not just after MR. Mr. Trump finally threw him out in a peremptory tweet. Mr. Esper is, of course, entitled to represent his actions in as self-flattering a way as he can, is entitled to a fair hearing, and is certainly entitled to disapprove of and criticize the former president.

What we seem to have here, though, is a particularly obnoxious case of a run-of-the-mill military-industrial complex cross-bencher lobbying and insinuating his way to the highest office in the Pentagon with a comprehensive masquerade as a Trump supporter while using his position to virtue-signal to the Trump-haters.

Mr. Esper clung to the Pentagon office furniture while undercutting the president through the election campaign when it would have been politically inopportune for Mr. Trump to fire him. Only after he was fired three days after the election did he claim to have been the leader of an internecine anti-Trump guerrilla movement.                                                 

His greatest declared disagreements with the former president were that Mr. Trump allegedly wished to deploy 10,000 active soldiers to deal with the extensive riots that followed the horrifying death of George Floyd in Minneapolis, which many Democratic mayors did nothing to quell. Mr. Esper claims that Mr. Trump proposed shooting rioters though preferably not fatally.

Attorney General Barr, who had and has documented substantial disagreements with Mr. Trump but without coming to conclusions as vituperatively hostile to the president as Mr. Esper’s, disagrees with the first point and says that the then president only wished to have the soldiers on “standby,” and none of the approximately 10 other people present corroborate Mr. Esper’s version of Mr. Trump proposing deliberately to shoot demonstrators.

The refusal of most Democratic mayors, such as New York’s de Blasio and Washington’s Bowser and Portland’s Wheeler to take serious measures to restrain rioters while the anti-Trump media chorus blamed the chaos on Mr. Trump naturally caused the president to consider means available to him to restore order.

The former secretary of defense emerges even from his own book as an oleaginous careerist creeping upwards in the regime under false colors, conspiring against his own leader when he was in deadly political combat with the most unscrupulous campaign strategists in modern American history, who were in unholy alliance with Trump-hating Republicans sheltering within the administration and the Republican congressional caucuses.

Mr. Esper appears to have been a cunning and efficiently destructive Trojan Horse within the Trump administration; he cannot now parlay that into a levitation as the conscience, such as it was, of the pre-Trump Republican Party. His real oath was to himself and his self-interest, and his book is more hypocrisy and fabrication than history. It is Mr. Esper who is now unfit for public service and even for military-industry lobbying. His book is an outrage.