Anyone that calls your brother a racist before walking/patrolling a mile in his boots is the problem with the world.

I just did call OP's brother a racist, and I've lived my entire life in Paris, so I guess I'm the problem. For the record I'm a white person with white parents.

Of course there are problems with radical Islam in many places in the world, including Paris.

Still, it's quite a jump from that to "It's overrun with North African immigrants. There's really no French culture left in Paris."

There are neighbourhoods with higher criminality, and these tend to be neighbourhoods with a lot of people of African origins, because a lot of these sons and daughters of immigrants tend not to integrate very well within the rest of the population. Some of it is their fault, and a lot of it is the racism of people like OP's brother. Why would you want to integrate a nation where a lot of people will judge you for your origins. Why would you do anything, when having a foreign-sounding name will prevent you from finding a decent apartment or land a decent job?

Also, "there's no French culture in Paris?" That guy has NO CLUE what he is talking about. Too busy hating people of colour, are we?