I'm only a little hesitant to believe this because people say this about lots of places in San Francisco ("don't go there, it's dangerous") etc. and my parents in their 60s go there quite often and they don't think it's particularly bad. And I recall people saying that about London too and the so-called no-go zones were not really that.
I don't think it's political. I think some people have just grown up in very safe environments and have a smaller comfort zone.
Of course if you're intimately familiar with this by living in France or something I wouldn't question it, but if you're just looking in from the outside, then it's all shadows on a cave wall.
So, all of these places I saw portrait as such in media, mostly conservative to right leaning ones in Europe, or FOX news, turned out to be no no-go areas in reality.
Using footage from demonstrations that got out of hand, civil unrest at one point and overblown as well as wrongly cited numbers are all that is to that.
And yes, in Europe there is no such thing as no-go zone where police don't go and all you have is anarchy.
He is using multiple times the expression "quartiers de reconquête républicaine" ("suburbs for the Republic to re-conquer").
If the President of a country considers he needs to reconquer parts of his own country, don't you think there is a bit of a problem, beyond whatever Fox News might say?
You might think there is some nuance because the areas with risk of Islamic separatism are not _necessarily_ the same as the high-crime areas where the police cannot easily go. But in practice they definitely are. It's not a pleasant situation, but it's the situation.
I can give more background if you are interested, but it is a well-studied problem with no solution in sight.
