JFK Assassination Files Reveal Scope of CIA-Mexico Surveillance in Pre-Tlatelolco Period

The National Security Archive publishes a briefing book drawing on 80,000+ pages of newly declassified JFK assassination records, revealing the depth of CIA-Mexico intelligence collaboration during the period immediately preceding the Tlatelolco massacre. Key findings: (1) Operation LIENVOY — one of the CIA's largest joint surveillance operations in history — was initiated by the Mexican president himself, not the CIA; (2) Operation LIANCHOR (1967–1968) secretly recruited Mexican writers and intellectuals connected to the 1968 student movement milieu as CIA assets; and (3) a LIANCHOR progress report covering December 1967 to May 1968 — the months immediately before Tlatelolco — is among the declassified documents. The briefing book, authored by NSA analyst Kate Doyle, directly contextualizes the Cold War surveillance apparatus and CIA-DFS intelligence-sharing relationship that enabled the Tlatelolco repression. The disclosures strengthen the historical case that US intelligence agencies were complicit in the conditions that produced the massacre.