Colombian conflict dialogue, but President Barco sent an ultimatum to the guerrillas and demanded that they immediately disarm or face military retaliation. Regional guerrilla and Army skirmishes created a situation where each violation of the ceasefire rendered it null in each location, until it was rendered practically nonexistent. By 1990, at least 2,500 members of the FARC-founded Patriotic Union had been murdered, according to historian Daniel Pecáut, leading up to that year's assassination of presidential candidate Bernardo Jaramillo Ossa. The Colombian government initially blamed drug lord Pablo Escobar for the murder but journalist Steven Dudley argues that many in the UP pointed
Cali Cartel FARC demanded in exchange for the safe return of Christina a ransom of $10 million. In response, the Cali Cartel kidnapped 20 or more members of the Colombian Communist Party, Patriotic Union, the United Workers Union, and the sister of Pablo Catatumbo, a representative of the Simón Bolívar Guerrilla Coordinating Board. Eventually, after talks, Christina and the sister of Catatumbo were released. It is unknown what happened to the other hostages taken by the cartel. During the narco-terror war waged by Pablo Escobar on the Colombian government, it is believed a hired assassin attempted to kill Herrera while he was