Mercenaries are not at all a new phenomena in Latin America. Already in the 16th century Latin America was invaded with mercenaries. The Spanish and Portuguese Conquistadors were a special breed of men: brutal, ruthless adventurers who would stop at nothing to carve out wealth and fame for themselves and an empire for Spain. In most cases, the conquistadors were not soldiers from the national armies of these invading countries, but mercenaries who set out on these conquests to build their fortunes with the spoils of war. They had to buy their armor, sword, and horses. However, in some cases the national military of a country would descend upon a native country and wage war with them and then claim the land as theirs. The most famous example of this is Hernan Cortes and his army, which was funded by the nation of Spain in their quest to bring the Aztecs down. Men like Hernán Cortés and Francisco Pizarro left their bloody mark on the New World.
US Private Military Companies (PMCs)
A US PMC is a company that is contracted to deliver military services to the Ministry of Defense (Pentagon) or in some cases the Ministry of State. In essence we're talking about mercenaries, while there can be discussion about the exact definition. The contractors are mostly former well-trained US militaries. They could be advisers, trainers, pilots, service personnel, security guards, reconnaissance or intelligence workers and so on.