Except for homicide, this is not true nowadays. See http://economicpolicy.oxfordjournals.org/content/26/67/347.a... for a recent study on the subject, which notes your opinion as a "common perception" that does not match the actual data.

Also by far the most populous.

You have to think about this in the context of history. The US has largely been diverse throughout most of its history. Most developed countries are largely dominated by one race.

i don't understand this argument, can you elaborate? it looks like you're suggesting that usa is a nexus of interracial violence and other race-motivated crimes.