“A Warning” is also likely to become the latest explosive tell-all about the Trump administration, following headline-grabbing books by former government officials such as Mr. Comey, the former deputy F.B.I. director Andrew G. McCabe, the former Trump aide Cliff Sims, and the former reality TV star and White House official Omarosa Manigault Newman.

In the 2018 Op-Ed, the author described a systematic effort within the administration to “preserve our democratic institutions” by defying some of Mr. Trump’s directives. “There is a quiet resistance within the administration of people choosing to put country first,” the author wrote.

The essay sparked criticism from both liberals and Democrats who felt the administration official should resign and come forward publicly, and from Trump supporters who denounced the official as a “deep state” operative undermining the president’s agenda. Mr. Trump himself argued that the official was guilty of “treason” and posed a national security risk, and he suggested that his then-Attorney General Jeff Sessions should use law enforcement to investigate the official.

The unnamed official, whose identity is known to the Times editorial page department but not to the news department or the reporters who cover the White House, has managed to remain anonymous for more than a year in spite of frenzied efforts to uncover the person’s identity.

On Twitter, much of the discussion after the news was published Tuesday revolved around guesses about the author’s identity and decision to remain anonymous. “At a time when State Department employees are risking their careers to testify about wrongdoing in this administration, I can’t think of anyone I want to hear from less than this person,” tweeted Matthew Miller, a former director of the Justice Department’s Office of Public Affairs in the Obama administration.

It’s unclear whether the official remains in the administration, given the high turnover in Mr. Trump’s cabinet, and how much additional and specific detail the book will offer regarding the president’s behavior and misgivings that members of his own administration might have.

Keeping the author’s identity under wraps may prove tricky with the release of a book-length work — Amazon lists “A Warning” as a 272-page book — which offers a greater opportunity for clues to his or her identity as well as increasingly sophisticated forensic author identification software, which matches prose style to other published works. Such software has been used to solve literary mysteries and unmask authors writing under pseudonyms, including J.K. Rowling, who published mystery novels as Robert Galbraith.