Undoubtedly the most significant event of the twentieth century in Colombia was the assassination of Liberal leader Jorge Eliecer Gaitan in an assassination that have not cleared. The event, which occurred on 9 April 1948, precipitating the country into an unprecedented violence that preys especially with the peasants who faced death and the two traditional parties. The National Front, a pact between two parties, reconciled to the chiefs, but left out many sectors, which would be the seed of the Liberal and Communist guerrillas to last the rest of the century. Strengthening drug gangs from the 70s would check to Colombian society and profoundly affect the ruling classes. But international pressure, especially from the United States and the work ethic of some politicians, journalists, judges and officials not bowed to the advancement of mafias and causing a bloody war against the state in the 80s and especially to the death of Pablo Escobar, the top leader in 1993. The government of President Cesar Gaviria conducted a process he called “economic opening” that made Colombia move from a protectionist to a globalized economy. Gaviria came forward with the Constituent Assembly in which he signed a new Constitution.

The government of President Andres Pastrana’s closest forward dialogues which have been with the guerrillas and especially with the FARC to create demilitarized zones. But these strengthened their military power in the country through bombings, kidnappings, intimidation and drug trafficking. Meanwhile, paramilitary groups were created, especially under the leadership of the AUC which was intended to fight the guerrillas. These groups were supported by many members of the military and police forces as well as politicians and landowners. The actions of the paramilitaries in Colombia and its battles against guerrillas, created a humanitarian tragedy of global proportions to make the country as one of the first number of displaced persons, war crimes such as massacres and terror in many parts of the country.