There is indeed no moral equivalence, but where does it come from?

This culture of extreme jihadist violence is not something that suddenly came to being.

He talks as if both sides are equal, except in the way they commit warcrimes, but that is not true. One is a massive state that has money and military power that eclipses that of the other. The other is a country that has been losing land, homes and dignity with every passing year.

Being disgusted by warcrimes is the privilege of an army that is able to still do war without commiting them. With the massive power imbalance comes a genuine desensitization of the underdog to violence, as they feel no other way to fight and have a chance at winning or making a difference.

I feel like the author is choosing exactly what part to compare in both groups (the morality of their war tactics) while silently hoping that the reader forgets any other differences between the two parties.