Robert Cox arrived in Argentina in 1959, hired as a copy editor by the Buenos Aires Herald, newspaper of the British community in Argentina. He later married Maud Daverio, an Argentine. His influence in the newspaper was vast, having them change their design and reach, from a small community-oriented newspaper, to a respected national daily. He was promoted to publisher in 1968. Under his direction, the newspaper moved in 1975 to a building with printing plant at 455 Azopardo Street, which remained the newspaper's offices for 34 years.
Cox had married into a wealthy family, and lived a privileged life; his social circle included elite families and military figures. Initially, he sympathised with the junta because of social connections, threats from the leftist guerrillas, and an expected end to repression of Isabel Peron's government. But he and his newspaper reported clearly and often on the dirty war's atrocities, and editorialised about them, despite the junta's prohibitions.
At his initiative, the Buenos Aires Herald was the first media outlet in Argentina to report that the de facto government was kidnapping people and making them "disappear". As a reporter, Cox went to the public meetings by the Mothers of the Plaza de Mayo and, also personally checked that the military authorities were using the crematories at the Chacarita Cemetery to incinerate the bodies of the "disappeared".
Cox was detained in 1977:
From that moment, Cox and his family lived in a permanent state of threat, suffering an attempt on his life, and his wife a failed attempt at kidnapping. When the threat of murder was imminent, he left the country. The decision was taken when one of his sons, Peter, received the following note, crudely simulating a note from the Montoneros guerilla group:
Dear Peter, we know that you are worried about the things that happen to the families of your friends, and that you are afraid that something similar could happen to you and your father. We do not eat children raw at breakfast. Considering the fear you all have, and that your dad is a high-level journalist, who is more useful to us alive than dead, we have decided to send you this little note as a warning. For this reason, and in consideration to the work your father does, we offer him (and all of you: Peter, Victoria, Robert, David and Ruth) the option to leave the country, where you run the risk of being assassinated. Do what you prefer, and tell “daddy” and “mummy” to sell the house and the cars, and to go work in Paris in another of the Herald's newspapers. You can also elect to stay here, working for human rights, but we do not think that is what your parents or your aunts and uncles expecting you in England for Christmas would like. A big revolutionary salute to your dad.
Cox and family left. He held a Nieman fellowship at Harvard in 1980. They settled themselves in Charleston as mentioned above, working for a sister publication as editor of the international section, covering news like the civil wars in El Salvador and Nicaragua.
In 2005 the Legislatura of the city of Buenos Aires after the initiative of the vice-chief of the Cabinet, Dr. Raúl Alberto Puy, paid homage to Robert Cox as a journalist during the years of the military dictatorship. Cox received the prize "in the name of the journalists that disappeared".
In 2005, his wife, Maud Daverio de Cox wrote a book about his life in Argentina during the years of the military dictatorship titled "Salvados del infierno" ("Saved from Hell").
In 2008, his son David wrote a book about his father's experiences in this period in Argentina titled "Dirty Secrets, Dirty War: The Exile of Robert J. Cox"
In 2010, Cox was designated "an Illustrious Citizen of the Autonomous City of Buenos Aires" in recognition of his humanitarian work.
2016 "Messenger On A White Horse" Documentary film by Jayson McNamara at BAFICI.This documentary examines Robert Cox's (editor of Buenos Aries Herald) role in the unmasking of the 1970's Argentinian military dictatorship's assassinations of the "disappeared".