Of course there are justification.
The conquest of one of the most holy places by another religion is a reason for war.
Persecution of non-muslims in that area fir 100s of years
Continuous aggression vs the Byzantine Empire by the Seljuks, seems to have triggered the whole thing.
Ever heard of the Kingdom of Jerusalem?
The remains are still left as the Maronites in Lebanon.
Seems like You do not have any cause to celebrate either considering todays situation.
I don't have any problems with Jerusalem beeing in control by the Jews.
Have already visited Jerusalem and the Christian holy places there, something
You are unlikely to be doing in Your lifetime.
The core of the Crusaders were the Normans, aka Vikings. They had but a Christian appearance.
What do You expect from Vikings
.
A Blood Eagle, if you are lucky!
View attachment 360558
The Vandals were the forfathers of the Vikings.