The solipsism is sounding here. The world was not always as it is now. Conquest was the way the world worked for a very long time. You think these people had any concept of the damage they were doing? All you have to do is take the one extra conceptual step. Don't be so lazy.
Fuck YOU ameriKKKan, kiss my ass you worthless pathetic fool. Your country has killed thousands. You bombed the countries of MY people and you ignorant statesians DARE to call us terrorists and make bomb jokes about us? You truly are an ignorant mindless IDIOT. Not to worry though, your empire of “freedom and democracy” shall fall and your allies will fall too. DEATH TO AMERIKKKA! DEATH TO THE WEST!
Also I thought liberals hated "whataboutism", every time a leftist makes a good argument about the immorality of the west, liberals call it whataboutism, yet that's exactly what you're doing right now. "Whatabout your people huh?".
They knew damn well what they were doing, this is basically genocide apologia. Arguing in good faith, they say while blatantly ignoring what the settlers were doing.
Even in the earliest days of European colonialism, there was very much a concept of the damage being done, look up Bartolomé de las Casas and educate yourself.