is who benefits from this type of violent act?
Yep, you guessed it. uribito has been moaning and groaning that Santos is destroying his vaunted (to uribito) doctrine of "Democratic Security."
Btw, President Laureano Gomez sowed enough hatred in Colombia "to last for 150 years." (From an editorial in the Colombian newspaper El Colombiano about 50 years ago.)
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Snips from REGIME OF BAYONETS by Vernon Lee Fluharty (1957)
In essence, it was the Crusades, the Inquisition, and the Castilian Reconquest from the pagan Moors, all over again in miniature. The worst of the Hispanic character systematically loosed the cruelty, African and Semitic in origin, which can almost casually send a man howling to his death in flames; which shows its genius in obscene and inhuman tortures until human flesh can stand no more, and dies. The essence of it is in these words
The villages burned, the children mutilated in their schools, the jails filled to overflowing with prisoners denied a trial or a judge, the men castrated in cold blood, those tortured in police dungeons, the women killed after being subjected to ignominy, the gagged press, the dwellings leveled by some functionary under arms, these ... brought moral ruin and the most abject complicity. We all just let it go on, because we did not hear the weeping of wounded children, and because the river of blood did not physically reach up about our feet! These hundreds of thousands of dead, of exiled, of fugitives, killed or shriveled the souls of everyone. But especially they left their stain on the only spiritual and political power that might have been able to disarm the government and the parties. In place of religious and human reasons, the Church preferred "Political Reason."
It is difficult to distill the essence of this violent epoch in Colombian history, but something of the unbridled hate and savagery should be set forth in this study, for the wounds went too deep, were too basic, to be forgotten; they are still there, demanding the healing of some government or another. They may break and reopen under social friction at some unforeseen day in the future, and for this reason, they are important.
http://www.icdc.com/~paulwolf/colombia/regimeofbayonets.htm