Apparently this idea goes way back. My Cuban cousin Rudy, who also served in the US Army during the Viet Nam era, says the Spaniards instituted a similar policy during the Cuban War of Independence in the 1890s.

Country villages and plantations too small to garrison were depopulated, and the peasants rounded up into concentration camps where they could be guarded. The idea was to prevent country folk from providing rebels with recruits, shelter or food. The detainees were fed by relief agencies from Europe and the US, although food was scarce, (especially after the US instituted a naval blockade). Hundreds of thousands died of starvation and disease. That figure is not an exaggeration.

Anyone caught in the deserted villages was shot on sight as a rebel, and the houses and fields were burned to deny shelter and food to the rebel forces (which, by the way, were not guerrilla bands, but organized military units.)

The war was brutal and long. To this day, the Catholic Church does not enjoy the support it does in other Latin American countries because the church sided with the Crown.