A committed Marxist–Leninist, Ramírez Sánchez was one of the most notorious political terrorists of his era, protected and supported by Stasi and KGB. When he joined the Popular Front for the Liberation of Palestine (PFLP) in 1970, recruiting officer Bassam Abu Sharif gave him the code name "Carlos" because of his South American roots. After several bungled bombings, Ramírez Sánchez led the 1975 raid on the Organization of the Petroleum Exporting Countries (OPEC) headquarters in Vienna, which killed three people. This was followed by a string of attacks against Western targets. For many years he was among the most-wanted international fugitives. Carlos was dubbed "The Jackal" by "The Guardian" after one of its correspondents reportedly spotted Frederick Forsyth's 1971 novel "The Day of the Jackal" near some of the fugitive's belongings.