[2] After his resignation, he returned to the International Foundation for Electoral Systems as a senior strategist and was a visiting faculty member at the University of Maryland.

[6] He graduated from DeWitt Clinton High School and City College of New York, then received a Ph.D. in American studies from Yale University.

Reviewing the case, John Ehrman wrote at the official CIA website that initially, Weinstein "believed that Hiss had not been a Communist or a spy.

"[11] Weinstein's extensive research included interviews with former Soviet intelligence officers who had worked with Chambers and a Freedom of Information request that eventually yielded 30,000 pages of FBI and CIA files.

In 1997, editor Victor Navasky published what he claimed as evidence that Weinstein had misquoted, misrepresented, or misconstrued several of his interview subjects for Perjury.

[13] Other sources, including Harvard professor Daniel Aaron,[14] Sidney Hook,[15][16] Irving Howe,[17] Alfred Kazin[18] and Garry Wills,[19] support Weinstein's scholarship.

Ellen Schrecker has "explicitly acknowledge[d] that the 1999 publication of Allen Weinstein's The Haunted Wood finally convinced me of the guilt of the major communist spies.

"[20] In 2009, historian Eduard Mark wrote that "The declassification of Venona excepted, no development since the end of the Cold War has affected the study of Soviet espionage in the United States as much as the work jointly written by Allen Weinstein and Alexander Vassiliev, The Haunted Wood.

Eventually, despite resistance from the White House Counsel, he agreed to resign, but the reasons why were not publicly disclosed until FOIA requests were made in 2017–2018.

During his tenure as a professor at the University of Maryland afterward, according to anonymous sources quoted in an article in The Daily Beast, Weinstein allegedly sexually assaulted a graduate student in 2010.