what about southern europe, my mestizo friend, the colonisation of Iberia, south Italy and the Balkans from Turko-Arab invaders, or the Mongol-Tatars in eastern Europe?
How about the Persians during Ancient times, or the Huns in early Middle Ages?
Europe learned the hard way, that in order not to be colonized, one must colonise the world, to subjugate it politically. And it almost did.
Were great crimes commited by the imperialist colonisation, yes.
Were great crimes commited by non-europeans to europeans, yes.
But it was a defensive reaction, and the best defense is to attack.
By the way, the Roman Empire did the same, their conquests were attacks to stop incursions of foreign tribes into roman lands, in the begining atleast. Gaul and Carthage were big threats to Rome.
Countless historical examples.