The democratically elected, left wing government of President Salvador Allende was overthrown in 1973 by the Chilean military, with covert CIA backing. A US-supported dictatorship led by General Augusto Pinochet was subsequently installed.

President Richard Nixon's daily briefs related to the coup on September 8th as well as the 11th – the day the Chilean military seized control of the government – were released. This declassification followed repeated calls for increased transparency by progressive members of Congress, human rights groups, and Santiago.

Nixon and then National Security Adviser Henry Kissinger strongly opposed the leftist Allende government and attempted to prevent its rule. George Washington University's National Security Archive issued a statement which says "[the documents] contained information that went to President Nixon as a military takeover that he and [Kissinger] had encouraged for three years came to fruition."