Just read the article - the Washington post did quite a bit of editorializing.
> Le tout-sécuritaire ne suffira pas
Translated roughly as "Total security will not suffice" (or the "state security apparatus" will not suffice). His argument isn't that inequality created ISIS. But rather that:
> C’est une évidence : le terrorisme se nourrit de la poudrière inégalitaire moyen-orientale, que nous avons largement contribuée à créer. Daech, « Etat islamique en Irak et au Levant », est directement issu de la décomposition du régime irakien, et plus généralement de l’effondrement du système de frontières établi dans la région en 1920.
He says the evidence shows that terrorism preys on the "powder keg" of middle-eastern inequality, and that the invasion of Iraq (and destruction of the previous regime) lead to the creation of ISIS. Not exactly ground breaking.
Anyhow, I'm not going to translate the whole thing, but near the end this:
> Rien ne peut excuser cette dérive sanguinaire, machiste et pathétique.
"Nothing can excuse this bloodthirsty, masochist and pathetic act"
> Tout juste peut-on noter que le chômage et la discrimination professionnelle à l’embauche (particulièrement massive pour les personnes qui ont coché toutes les bonnes cases en termes de diplôme, expérience, etc., comme l’ont montré des travaux récents; voir également ici) ne doivent pas aider.
"We can only note that unemployment and discrimination don't help"
> C’est par le développement social et équitable que la haine sera vaincue.
"It's through social development and equality that hate will be defeated"
Again, not ground breaking. It took the west several reformations of our culture/religion, and 2 world wars to finally get our heads out of our proverbial asses. Also, social welfare has played a huge part in the rise of a real 'middle class'. We aren't as capitalist as we think, and 'socialism' is part of the reason inequality isn't as bad today as in 1900. But, as the data shows, inequality is on the rise yet again (as conservative politics are also on the rise).