Ultimately, the origins of the West lie in the Carolingian empire. A lot of justification for the Crusades is almost identical to modern Western imperialism. The crusades had to happen because the savage Mohammedans do not respect pilgrims just like invasions had to happen because the savage Muslims do not respect women. The crusader states were just the medieval version of the mandates where a bunch of Western Europeans rampaged through the Levant as if they owned the fucking place. There's also typical Western hypocrisy where the nascent West styled itself as Christendom even though Christendom never was applied to the Orthodox East, culminating in the sack of Constantinople during the Fourth Crusade.

I suspect the inability to politically unify Europe also played a role since a lot of the tribalism that exists in European society is a consequence of this. You're not going to have a European polity like the Song dynasty that focused less on the military and focused more on the economy and culture as part of regional hegemony. This focus less on the military, intentionally done to not repeat the mistakes of the Tang dynasty like the An Lushan rebellion, was how they eventually got rolled by the Mongols. But because European history is just the warring states period except if it lasted for more than 1500 years, its history is nothing more than state and statelets constantly warring with one another. Europe has never been at peace because there's always at least one statelet that had beef with another statelet. It also doesn't help that those European states had weak central governments too. So, it's not just statelet vs statelet, but statelet who can barely control their rampaging feudal warlords vs statelet who also can barely control their rampaging feudal warlords. It's somewhat unusual that Western Europe didn't have eunuchs while the Byzantines and Chinese dynasties did. It's because while the Byzantines and Chinese dynasties had strong central authorities which necessitated an imperial bureaucracy staffed by eunuchs, you don't need an army of eunuchs to administer the Duchy of Burgundy or the Duchy of Benevento.

All this paint a picture of Western Europe being the land of warlordism. Outside of inheritance, you basically can only acquire land through direct conquest or service to your feudal liege. Or in other words, either by being a feudal warlord or service to a feudal warlord. At a certain point, it just becomes part of European culture. This is why Zheng He showered gifts to the local while Christopher Columbus immediately started butchering and enslaving the first Indigenous person he saw. One was acting as an emissary of a prosperous empire while the other was some rampaging bandit who borderline grifted a pair of warlords whose kingdom was facing financial collapse after spending decades warring against the remnants of Muslim rule. Columbus's so-called discovery of the Americas of course snowballed from there with the genocide of the Indigenous and the slave trade and so on.

tl;dr The savage occidental knows nothing of peace and must be rescued from barbarism by their civilized superiors.