To clarify, I'm not saying that racism is not a problem in the U.S. Certainly it is.
If other countries don't have huge number of minorities in prison, then it is because (1) they don't have huge numbers of minorities, or (2) they don't have a lot of people in prison.
But in the U.S. we have both the world's highest incarceration rate and an unusually ethnically diverse population. Add to that the racism that everyone has, and we get the kind of problems you mention.
To clarify, I'm not saying that racism is not a problem in the U.S. Certainly it is.
If other countries don't have huge number of minorities in prison, then it is because (1) they don't have huge numbers of minorities, or (2) they don't have a lot of people in prison.
But in the U.S. we have both the world's highest incarceration rate and an unusually ethnically diverse population. Add to that the racism that everyone has, and we get the kind of problems you mention.