Colombia's civil war is an expression of the profound polarization of the country's social classes. On the two occasions during the 20th century when there were attempts at building a lawful social democratic state —during the 30s and 90s— the ruling classes answered with intolerance and savagery with the aim of blocking any change which might affect its vested interests and power while the government of the United States has consistently and readily responded to the requests of the Colombian oligarchy to subjugate any insurrections and maintain an order built on oppression and exclusion.

The Plan Colombia is one more link in this long chain of infamy. It implies a new phase, more internationalized, technological, psychological, cultural and intensified in the irregular conflict of this civil war, that which erodes any margin for neutrality and reinforces the struggle between the different social classes. To further develop this analytical approach to civil war in Colombia, herein i) this war is described as an expression of social class struggle in Colombia; ii) the Plan Colombia is characterized as intensifying said conflict; iii) within a context of increased US interventionism; iv) as an expression political economy war interests; v) concluded by one of the new elements which only serves to make the conflict all the more complex and destructive: biological warfare.