A President’s Daily Brief is not a historian’s judgment written after the fact. It is what the Central Intelligence Agency told one reader, on one morning, about what it believed was happening in the world. Two such briefs went to Richard Nixon in September 1973, and read together they do something a single document never could: they show the Agency being wrong, in writing, about the most consequential event of that month.
Two memos, two findings
The record consists of two CIA President’s Daily Briefs, known by the acronym PDB, each marked Top Secret, a classification reserved for information whose disclosure the government judged could cause exceptionally grave damage to national security. One is dated September 8, 1973. The other is dated September 11, 1973. Both were declassified on August 25, 2023, nearly fifty years after they were written. The September 11 brief was released in full. The September 8 brief was only partially declassified, meaning some portions remain withheld; the source material does not say how much.
The September 8 brief told Nixon there was no evidence of a coordinated three-service coup plot against President Salvador Allende. It added a specific warning: if “hotheads” in the navy acted on the assumption that the other services would automatically fall in behind them, they risked finding themselves isolated. The September 11 brief, delivered to Nixon the same morning Chilean officers moved against Allende, struck a different note. It said military officers were determined to restore political and economic order, but cautioned they might still lack an effectively coordinated plan to capitalize on civilian opposition to Allende.
Seventy-two hours
Set side by side, the two briefs cover just three days. On September 8, the CIA’s assessment to the president was that no tri-service plot had been detected. On the morning of September 11, with a coup already under way, the Agency was still describing the plotters’ coordination as uncertain. The coup succeeded that same day. The record does not explain how an assessment of an uncoordinated plan, delivered hours before the event, fits against the fact that the event came off. It simply contains both documents, dated as they are.
Why the mismatch isn’t explained
Several ordinary explanations could close this gap, and none of them is confirmed by anything in the released text. Field intelligence may simply have lagged behind the plotters, who had reason to keep their planning compartmented even from sympathetic foreign observers. A briefing can also be written cautiously to avoid overstating what is only partly known, which would explain the hedged language rather than certainty either way. It is possible the September 8 assessment was already out of date by the time it reached Nixon’s desk. Each of these is plausible. None is stated. The PDBs contain no retrospective note correcting the September 8 judgment, no memo acknowledging that the Agency had misjudged the plotters’ coordination. The documents assess; they do not later annotate themselves.
The 2023 release, and its silences
The declassification followed a formal request from the Chilean government of President Gabriel Boric, filed ahead of the coup’s fiftieth anniversary. The U.S. State Department’s press release, dated August 25, 2023, framed the release as consistent with “our commitment to increased transparency” and said the review was conducted “in response to a request from the Government of Chile and to allow for a deeper understanding of our shared history.” Chile’s undersecretary of foreign affairs, Gloria de la Fuente, thanked the Biden administration for accepting the request. What the statement does not do is explain why these two documents were withheld as Top Secret for close to fifty years, through earlier rounds of Chile-related declassification going back to at least 1999.
What Chile is still asking for
Peter Kornbluh of the National Security Archive, who had filed a Freedom of Information Act request, known as FOIA, for the two PDBs earlier in 2023, has noted that other coup-related U.S. records remain classified, including material tied to the deaths of American citizens Charles Horman and Frank Teruggi and to U.S. support for the Chilean secret police agency, DINA, formed after the coup. The source material does not specify how many additional records Chile has requested, what they contain, or any timetable for their review. That request stands as an open administrative matter, not as a sign of what further files might show.
Kornbluh’s reading, kept at arm’s length
Kornbluh’s comments on the release are his own reading, offered after the documents came out, not a finding written into the files themselves. He said the two PDBs “contain not a single sentence that could compromise U.S. national security,” and credited the release to FOIA pressure combined with Chilean diplomacy. He called the continued secrecy of other Chile-related files “inexplicable” and said he hoped the Biden administration would release them. Those are his words, made in August 2023, about documents the Agency chose to keep classified for decades. The briefs themselves offer no comment on that choice at all.