One defining characteristic of America's foreign policy, historically, has been that nonpowers- countries that stood no real threat to the United States and had little diplomatic heft- were little more than playthings; chess pieces to be moved around at leisure in response to actions by other powers (who often took the same view, particularly the Soviet Union).
If you're fairly on the ball, you may know about the Tuskegee syphilis experiment. Between 1930 and 1972, poor black men, former sharecroppers from Macon County, Alabama, who were under the impression that the government was providing them with free healthcare were in reality being studied by the Public Health Service for the effects of syphilis on the human body, when left untreated. Despite doctors knowing that 399 of the 600 men had it, they were deliberately left untreated, even after the discovery of penicillin as a treatment for the disease, and were actively kept away from penicillin treatments available to the general population. The study would have gone longer than 1972 (by which only 74 of the 399 were still alive) had someone not finally leaked to the media.
The RNG today takes us one step further, as in Guatemala, from 1946-48, the Public Health Service didn't wait around for locals to contract syphilis. They instead actively infected people with it, and then gave them antibiotics, in order to test penicillin as a treatment. Or at least, about half of them got it. There wasn't enough penicillin to treat all the subjects while still keeping the U.S. Army supplied with it. In a PDF file detailing the study we'll be linking to shortly, one Public Health Service man on the ground was shown to say "We shall use our supply sparingly so as to have it available at all times for use in demonstration programs and to build good will."
This pops up here because it was previously thought that about 1,300 people were infected as part of the study, though even this wasn't known until Susan M. Reverby of Wellesley College stumbled across old records detailing it while studying the Tuskegee experiments. (The Obama administration issued a formal apology to Guatemala last year.) Reverby's report on her findings can be found in this PDF file. However, going through those records further, the number has shot up to 2,082... and six of them are known to still be alive. Guatemalan president Alvaro Colom, who called the experiments a "crime against humanity" when receiving the apology from the United States, is currently looking into ways the survivors can be compensated.
Aside from giving them those 65 years back.