NEW YORK — Hillary Clinton is calling her new book ‘‘What Happened’’ and promising unprecedented candor as she remembers her stunning defeat last year to Donald Trump.

‘‘In the past, for reasons I try to explain, I’ve often felt I had to be careful in public, like I was up on a wire without a net,’’ Clinton writes in the introduction, according to publisher Simon & Schuster. ‘‘Now I’m letting my guard down.’’

Simon & Schuster said Thursday that Clinton’s book will be a highly personal work that also is a ‘‘cautionary tale’’ about Russian interference in last year’s election and its threat to democracy.

In public remarks since last fall, the Democrat has cited Russia as a factor in her defeat to her Republican opponent, along with a letter sent by then-FBI Director James Comey less than two weeks before the election.

Comey’s letter, sent to Congress on Oct. 28, said the FBI ‘‘learned of the existence of e-mails that appear to be pertinent to the investigation’’ into the private e-mail server that Clinton used as secretary of state. Days later, Comey wrote that the FBI did not find anything new.

‘‘What Happened’’ is scheduled to come out Sept. 12 and has evolved since first announced, in February. It was originally billed as a book of essays that would ‘‘tell stories from her life, up to and including her experiences in the 2016 presidential campaign,’’ as opposed to a memoir centered on the race.

Clinton’s loss has already been the subject of the best-selling ‘‘Shattered,’’ a highly critical book by Jonathan Allen and Amie Parnes, and a more sympathetic account, Susan Bordo’s ‘‘The Destruction of Hillary Clinton.’’

associated press