Before the fall of Soviet Union seeing someone black on the streets of Moscow or St. Petersburg was like seeing a Martian. It was super homogeneous, 99%+ of the population was white white. That's where these crimes are happening now.

They have a problem where the "outsiders" are really prone to violence. No different from the situation in Philly, where the black population is prone to violence. The problem there is that the population is not segregated. It's not a mobile society. All kinds of people live together, in the same high rises, on the same floors. In Philly we have high crime neighborhoods, and the crime does not really leak outside, so most are not bothered by it. There, the crime is everywhere, you can't just stay out of the bad areas like you can in Philly.

If everyone from the bad neighborhoods could move into the better neighborhoods in Philly, we would have the same backlash here. Clash of "cultures". Of course physical violence is not the solution.