Colombia and the United States have worked out a agreement to move American naval reconnaissance aircraft, that used to operate out of Ecuador, to several Colombian air bases. For the last ten years, these aircraft have patrolled the west coast of South America, to search to drug smuggling boats. The aircraft also watch out for legal traffic, and provide assistance for ships in distress. The U.S. would pay Colombia $40 million a year for the use of those bases.
Ecuador ordered the American aircraft out because the new president there, Rafael Correa, was elected with the assistance of drug gangs, and getting rid of those American patrol aircraft has been a longtime goal of the drug smugglers. Correa also allowed leftist Colombian rebels, like FARC, to set up bases in Ecuador. This was exposed when Colombian troops captured FARC documents, when one of those border bases was raided. Correa was very angry about this, and tried to divert attention from his close relationships with the drug gangs and FARC, by accusing Colombia of being an American puppet and assisting the Americans in taking over South America. Or something along those lines.
The American force in Ecuador was small, usually a few AWACS and P-3 aircraft to monitor the air and sea, and about 200-300 U.S. military personnel. These will move to Colombia, where about a thousand American military and civilian personnel assist the Colombians in their struggle against the drug gangs.