The opening skirmishes in a battle between President Trump and his former national security adviser John Bolton were being fought on Friday — and there are plenty more to come. 

Bolton’s book, “The Room Where It Happened,” will be published on June 23.

According to marketing material from his publisher, Bolton will allege that Trump’s purported misdeeds regarding Ukraine — the issue that led to his impeachment in December — were replicated “across the full range of his foreign policy.”

The publisher promises that Bolton “documents exactly what those were” and also stresses that the author was “astonished” to see “a president for whom getting reelected was the only thing that mattered, even if it meant endangering or weakening the nation.”

The book seems sure to elicit a counterpunch or two from the president. It would not be the first time Trump has put Bolton in his social media crosshairs.

In January, Trump complained on Twitter: “I NEVER told John Bolton that the aid to Ukraine was tied to investigations into Democrats, including the Bidens. In fact, he never complained about this at the time of his very public termination. If John Bolton said this, it was only to sell a book.”

That came after The New York Times reported that an unpublished manuscript from Bolton alleged that Trump personally said he wanted to freeze congressionally mandated aid to Ukraine until officials in the eastern European country would launch such investigations. 

Trump had previously stressed on Twitter that Bolton had been fired in September.

The Bolton versus Trump contretemps has a complicated moral and ethical contour.

During Trump's impeachment trial, Bolton signaled a willingness to testify if served with a subpoena, and if that subpoena were upheld in court. House Democrats ultimately did not subpoena him, fearing the legal process would drag on too long.

To his allies, Bolton raised legitimate questions. To his critics, he engaged in a stalling tactic intended to avoid testimony — and save important revelations for his book.

Mark Zaid, a Washington, D.C., attorney who specializes in national security cases and has represented clients from both parties, was scathing of Bolton’s position — particularly given the gravity of what the book appears set to allege.

“He essentially withheld information that would have been directly relevant to the impeachment inquiry and he did so, ostensibly, for the sole purpose of publishing it in a book. I would characterize that as incredibly disappointing, and it could be perceived as unpatriotic,” Zaid said.

The question of whether to testify, Zaid added, “was a decision that he had the authority to make.”

USA Today reported in February that Bolton had said in a speech to Vanderbilt University that he did not regret failing to testify because it “would have made no difference to the ultimate outcome.” 

Rick Wilson, a GOP strategist in Florida who has authored two books critical of Trump, said that during impeachment Bolton “had a remarkable opportunity to do a service to his country and make it very clear what he witnessed” and instead “chose to do it in his book.”

Wilson, who is also a leading figure in the group of anti-Trump Republicans called The Lincoln Project, added that when it came to Bolton’s overall view of Trump, “I completely believe it. There is no question that John Bolton was a witness to a spectrum of behavior that ranges from criminal to terrifying.”

Spokespeople for the White House and the National Security Council (NSC) did not respond to an email inviting comment Friday.

But virtually no one expects that silence to last. There has already been a prolonged battle over the book manuscript, with the NSC seeking changes purportedly to protect national security. 

A lawyer for Bolton, Chuck Cooper, wrote an op-ed that appeared in The Wall Street Journal on Wednesday in which he argued that this amounted to “a transparent attempt to use national security as a pretext to censor Mr. Bolton, in violation of his constitutional right to speak on matters of the utmost public import.”

Some GOP insiders express distaste for Bolton’s endeavor and feel some semblance of sympathy for Trump’s position. 

“I don’t like when people take advantage of a situation for monetary gain or out of vindictiveness,” said a veteran of a previous Republican administration who asked to remain anonymous. “Very few people leave office and write glowing books about their service because, if you call up a publisher, the first thing they say is, ‘What can you tell us that we don’t know and is really bad?’”

The book is the latest twist in a tumultuous career for Bolton, who was a deeply controversial figure during former President George W. Bush’s administration.

Bolton, who served as U.S. ambassador to the United Nations, was one of the most vigorous proponents of the Iraq War. He continues to advocate hawkish positions on Iran, North Korea and other foreign policy hot spots.

Bolton’s willingness to be critical of Trump has won him some unexpected admirers and alienated plenty of former allies within the GOP.

Sen. Chris Van Hollen (D-Md.) told The New York Times in January that it had become “a totally upside-down world” when it came to perceptions of Bolton. 

Bolton’s book also comes at a time when Trump has faced criticism from other figures in the foreign policy or military establishment, including former Secretary of State Colin Powell and former Secretary of Defense James Mattis. 

But some observers are skeptical that Bolton’s book will have real political impact, barring some truly explosive and well-documented revelation.

Sol Wisenberg, an attorney who served as deputy independent counsel under Kenneth Starr during the Clinton-Lewinsky scandal, said that he believed Bolton was already seen as very political and therefore did not carry the same bipartisan heft as someone such as Mattis. 

“He is more like the numerous people who have fallen out of Trump’s favor,” Wisenberg said of Bolton. “I’m somewhat interested in what he has to say. I just don’t know if it makes all that much of a difference.”

Wilson said there was at least one thing that Bolton could look forward to — the near-inevitable tweets from the president that might savage the book but would also, undoubtedly, help publicize it. 

“John should wake up every day, and hope Donald Trump is Donald Trump that day,” he said.

The Memo is a reported column by Niall Stanage, primarily focused on Donald Trump’s presidency.