The joy of English....
Is not only how flexible a language it is, but also how easily it can be misinterpreted from the speaker's intent, and still be within proper formal definition of the words. All the way down to "it depends what the meaning of "is" is!
Interesting about the use of the word "crusade"...I suppose it was, in the current modern usage of the word, on all sides. In Western society today, we use the word "crusade" as any struggle against a perceived wrong, something that is moral and ethical to do. And the religious aspect is seldom the main focus.
I believe that there should be a clearly understood difference between the use of "crusade" and "Crusade". I can clearly understand the difference in view point between those with a Christian heritage and those with a Muslim heritage. Christianity considered the Crusade(s) right, moral, and just. Of course, what went on during the Crusades was an entirely different matter ( its that whole "can't make an omelet without breaking eggs" thing, I think).
And, if one has even a bit of empathy, its easy to see how the Muslims on the other side of the Crusades wouldn't think that way. Probably why today's Muslims automatically associate the term "crusade" with a bad thing, and we don't.
Now there's an interesting dichotomy, we, (as Constitutionalists) believe strongly in the original intent of the Founding Fathers, given to us through their writings and our history. Muslim society is also very focused on original intent of their Founder(s). Very different starting points, to be sure, only having in common the belief in the rightness of the cause, and the emphasis on the original intent of the movement.
And that brings us back to the war (both then and now), or I suppose, all wars throughout time. The belief in the "rightness" of the cause, and the degree of willingness to go to any extreme in the process.
I used the term religious war in describing the war in the east in the sense that both the Germans and the Soviets had few, if any rules about the treatment of those in their power. Unlike the US, (and by extension the Western Allies) who used a codified set of rules for the treatment of prisoners and people of occupied territory (enforced by our laws), the Axis powers, and the Soviets seldom paid much attention to the few rules that they did have.
All sides commit violations of the proper treatment of prisoners and occupied peoples. The side that does it the least, and has an active policy to prevent it, are the good guys. The other side is, by definition, the bad guys. Especially when they are also the losers.
I don't mean to come off sounding like an apologist for either the Nazis or the Reds. I'm not. What I am is a realist. The capability for the greatest evil walks the earth daily, wearing human skin, in all nations and peoples. When the leaders, rulers, God, etc. tells us that it is not just allowed, but it the "right" thing to do, that evil is unleashed.
One of my hobbies for many years, has been the study of WW II, focusing mainly on the equipment. The guns, and all the machines of war used in that great conflict. One also learns quite a bit about all the other things involved as well. And some clear insights into the nature of man are revealed as well.
I have no empathy for those who ordered and condoned atrocities, only for those, on all sides, who were caught up in something so much bigger than themselves, doing what they had to do, being tarred with the same brush in history as those who were actually responsible.
But that too, is the nature of man. History is written by the victors.