Three years ago City Journal's Theodore Dalrymple wrote an outstanding piece called "The Barbarians at the Gates of Paris". He paints a detailed, dark picture of the unassimilated, well-armed masses* that reside in the government housing projects that ring Paris and many other French cities. Read it if you really want to understand what's going on over there right now.
*Oh, you did know that those rioting "youths" are pretty much all Muslims, didn't you? Not that you'd ever learn that from the MSM. There are so many parallels between what is happening in Paris and the Palestinian "intifada" that Steven Plaut has suggested that the French government pursue a "land for peace" resolution to the current crisis.