“No single mistake cost Mitt Romney the presidency,” former Romney advisor Gabriel Schoenfeld writes in the opening page of a tell-all book centered on one mistake on a single day in the 2012 campaign: The Republican’s hasty and flawed reaction to the terrorist attack in Benghazi, Libya.

But Schoenfeld argues nonetheless that Romney’s inability to respond cogently to the Benghazi attack was a key component of his defeat. “A man celebrated for his management prowess delegated an immense mount of decision-making power to individuals who failed to carry out successfully that and other basic functions,” writes Schoenfeld, who held the title of senior adviser on the campaign. The author substantiates his critique with a biting assault on Romney’s campaign team, especially campaign guru Stuart Stevens and especially policy director Lanhee Chen.

“Chen was no Henry Kissinger.” Schoenfeld writes, noting that the policy director preferred to be referred to with the honorific of “doctor.” “Indeed, he had once self-deprecatingly boasted in a meeting that he could not find Finland on a map,” Schoenfeld adds. Stevens, he continues, was controlling about cosmetic issues like how to distribute the campaign’s major policy book—bound or on digital USB sticks—but wasn’t concerned by its contents.

Despite his campaign title, Schoenfeld worked mostly outside the candidate’s inner circle. Reporters who covered the Romney campaign publicly wondered who the author was after news broke of his 74-page eBook, A Bad Day On The Romney Campaign: An Insider’s Account.

Much of the book involves the a behind-the-scenes narrative of the Romney campaign on September 11, 2012, when the Cairo embassy came under attack and four Americans were killed in Benghazi. Chen, Stevens and Richard Williamson, a former Bush and Reagan foreign policy official who Schoenfeld writes was a “doer not a thinker,” authored a statement, which was never circulated to foreign policy experts who would have spotted its errors.

The statement got major facts wrong, and used a national tragedy, the death of the Libyan ambassador and two other citizens, as a launching point for a tangential political attack. Pointing to a disavowed U.S. embassy statement from Cairo, which condemned an offensive video that had inflamed regional tensions, Romney blamed the Obama administration for “sympathizing with those who waged the attacks” as Americans were being killed in Benghazi. “The Romney campaign’s statement of September 11, 2012 had left the candidate naked, embarrassed, and disarmed,” Schoenfeld writes. He notes that Romney “dressed down his top advisers” on September 12th following the botched statement.

Other former Romney aides say the premise of the book is flawed. “It’s eight months after the attack and the whole Republican world has been banging on Benghazi trying to capture the imagination,” responded one senior Romney aide, who asked for anonymity. “How’s that working? You can’t make the campaign about something people don’t want the campaign to be about.”

Romney’s inexperience in foreign policy required a seasoned foreign policy hand with him at all times to prevent mistakes, Schoenfeld writes. Instead, it was usually just Chen on the plane coordinating with a host of formal and informal aides and advisers.

At the moment of the Benghazi fumble, Schoenfeld was no longer among those advisers. He joined the Romney operation in 2011 at the behest of Stevens and Chen with the intent on being moved into the chief speechwriter role. Well before the Republican convention, he was “burned through” he writes, and was replaced as a speechwriter by April of 2012. He later worked out of the first floor of Romney headquarters writing op-eds and other copy for the communications department—well away from the discussions that took place on the third floor or on the campaign plane. After the convention, Schoenfeld was one of the Romney aides rewarded with $50,000 bonuses for winning the nomination, money guaranteed to him in his contract with the campaign.

When Richard Grenell, the openly gay former spokesman for the US Mission to the UN, resigned his post as Romney’s foreign policy spokesman due to criticism from the media and social conservatives, Schoenfeld wanted the post — a way back into the inner circle — but was rebuffed, he writes. “After Grenell fell under the bus, I sought to move into the empty position, believing that the campaign sorely needed an experienced hand in this area. I found my way blocked by Chen, so I turned to Stevens for assistance, but he was disinclined to help,” he writes in a footnote.

The author traces a history of foreign policy dustups, including another premature Romney statement in April 2012 about U.S. assistance to Chinese human rights advocate Chen Guangcheng, his comments questioning security at the London Olympics, and his assertion that Palestinian culture was responsible for lesser economic progress.

After winning the first debate, Schoenfeld blames Benghazi for Romney failing to rise to occasion in the final two, causing him to stall out weeks before Election Day. In the town hall debate where Romney was corrected by CNN’s Candy Crowley for asserting that Obama did not call the attack an act of terror from the start, he writes that Romney was focusing on the less important issue and not on the security and intelligence failures at the consulate. In the third debate focused on foreign policy, Schoenfeld takes the candidate to task for his “insipid” and timid response to the opening question about Benghazi, blaming the flawed statement on September 11 for scaring him off the issue.

“A central lesson from this chain of folly, almost too obvious to state, is that foreign policy matters,” Schoenfeld writes. “It was a strategic mistake—political malpractice—on the part of Romney and his lieutenants to try to downplay its significance, and action they took early on the basis of an almost mechanical interpretation of poll data and the belief that President Obama possessed too many advantages in that area.”

Voters of all stripes gave Obama high marks on foreign policy following the killing of Osama bin Laden. Obama’s get-out-the-vote operation was superior, his messaging—particularly on social issues immigration reform — mobilized a youth army and gave him a record victory among minority voters. Romney’s singular focus on the economy may have been misguided, but Schoenfeld can’t substantiate the claim that a stronger focus on foreign policy or Benghazi would have won the day.

As another senior Romney aide said, after requesting anonymity, “[Of the] million reasons why we lost, this is just not one on my list.”

“Obama turned out to be not as unpopular as we thought it was, the economy wasn’t as bad,” the aide continued. “There were unseen demographic changes under our feet. A candidate who would have been a great president but wasn’t the greatest retail politician. They had five years to build a machine, which we started building in May after we stumbled out of the primaries. Foreign policy just didn’t matter.”

Schoenfeld writes that he “decided to decided to subordinate discretion and friendship—undoubtedly, in some cases, to sacrifice friendship—to provide an account of what happened that is as accurate and incisive as I can make it.”

The ebook, which was given to TIME by the publisher, is scheduled to go on sale May 14.

UPDATE 3:38 pm: After publication, deputy campaign manager Katie Packer Gage emailed to say “the notion that Gabe was a “senior advisor” to Mitt Romney is ridiculous.”

“If he had any specific expertise it was so overshadowed by his inability to work with people that it made it impossible to utilize him,” she added.

UPDATE 6:30 pm: Schoenfeld writes that he was indeed a senior adviser on the campaign and forwarded his pay-stub to prove it. It lists him as a “senior adviser/writer” in the communications department.

Unfortunately, the statement provided to you by Romney deputy campaign manager Katie Packer Gage was incorrect. She said “the notion that Gabe was a ‘senior advisor’ to Mitt Romney is ridiculous.” The fact that the deputy campaign manager has stooped to misrepresenting the very job title the campaign gave me—“senior adviser”—a title they put on their own employment documents, shows just how desperate some are to hide the truth.

Correction: A prior version of this post misquoted Schoenfeld that he had been “burnt out” as a speechwriter. He wrote he was “burned through.”