Quotations from Baruch Spinoza applicable to the riots that happened in France last week :
"I have taken great care not to laugh at human actions, not to weep at them, nor to hate them, but to understand them."
In these difficult moments for France, let me remind you that
"I say to the House as I said to ministers who have joined this government, I have nothing to offer but blood, toil, tears, and sweat. We have before us an ordeal of the most grievous kind. We have before us many, many months of struggle and suffering."
    Winston Churchill, to the House of Commons on May 13, 1940.

I have no solution to offer as well, but a very good study on "Multicultural France, geopolitical strength or weakness ?" (unfortunately in French)
Meilleur mémoire de géopolitique ex æquo écrit par un officier stagiaire français
CPM Florian CHARDÈS (commissariat de la marine / C5)
“ La France multiethnique de 2030 : force ou faiblesse géopolitique ”
Directeur: Ch. Réveillard

downloadable on www.college.interarmees.defense.gouv.fr
[direct link in pdf format]