The race problem in the US is basically the worst in the developed world...here in the UK I live in an inner city area of Manchester (a big city by UK standards) - about 6m folks within 30 minutes drive...and my street is genuinely mixed - Whites (polish, irish and germans to name a few), blacks (UK born, Trinidadians, Asians (Pakistani, Bangledeshi, Indian and Chinese) etc.
The States is much more segregated along racial lines.
When I went to the States once I was in DC (visiting the Smithsonian and a couple of friends I have out there) and thought I catch a movie one night when my friends were otherwise engaged.
I could see that there was a movie theatre a couple of stops along on the Metro in a Mall..so I went - Independence Day I think was the movie..this is maybe 15 minutes away from the US Center of Govt - I was the only white person in the theatre (which was full)
That level of segregation is really shocking to see - it strikes me that the issue of slavery and its effects - both economic and cultural - haven't really been dealt with and in a society teeming with guns and disaffected inner city youth it's hardly surprising that there are crime issues surrounding black ghettos..