Man, good thing you limited it to the last 40 years and not the last 60, where they killed tens of millions due to both insane incompetence and malice.
75 years ago the United States was part of the allied powers that helped put an end to a genocidal dictator with world domination plans. 200 years ago the United States was a major participator in the global slave trade and actively waging war and committing genocide against the ingenious people of North America.
No ethnic or national group of people have been virtuous throughout history. No ethnic or national group of people have been evil throughout history. Trying to cut history into a small slice in order to draw a moral contrast is misleading and ignorant at best.