There are different directions in which one can be radicalised, not just ISIS style radical Islam. The group don't hide they were calling for revolution, which is pretty radical.

> And what exactly has France done to fight ISIS anyway?

https://fr.wikipedia.org/wiki/Coalition_internationale_en_Ir... (curiously the English language article doesn't mention French forces in the outline, but does in the text)

Just sent an aircraft carrier, some ships and planes, and special forces. And intelligence. Contributed more than anyone outside of the US and local forces like YPG. Led one of the first coalitions that were extremely wide (including everyone from Bahrain through Belgium and Japan to Russia and China). But sure, you haven't heard about it, so they didn't do anything

> I guess that's a little better than what they did in Rwanda to support the genocide there

Wait, is France bad when it intervenes or when it doesn't intervene? In Rwanda they didn't "support" the genocide of course, just didn't do much to stop it after supporting the faction that commited it before.

> How is someone who fights against ISIS radicalized?

The Taliban are fighting ISIS... do you consider the Taliban to be radical ?

Some people in the thread should open a book or two, we're not in "bad guys vs good guys" world

They are far-left activists who went to fight alongside Kurdish militias of the YPG, a group affiliated with the PKK, considered a terrorist organisation by the European Union.

That is why they were put under surveillance when they came back to France.

Here is a reference in French: https://fr.wikipedia.org/wiki/Affaire_du_8_d%C3%A9cembre_202...

Ultimately it's a bit more complicated than good people fighting versus evil people (and as far as I'm concerned, they were effectively fighting for a US proxy against another US proxy).

In "pacific" Europe (specially in those countries where conscription is not mandatory) voluntarily taking weapons and going to a different country to kill people, no matter the reason, IS definitely considered radicalized, in the sense that it's very, very rare and "anti-social" behavior.