“But it was never theirs To begin with”
That statement applies to “Native Americans” arguably just as much as it does to white Americans today. It would be wrong to deny the people of any nation of the world, whose ancestors when they first arrived, defeated the original inhabitants, the right to defend their nation in the present. When the Japanese enacted mass immigration policies to the asian states they conquered during WW2, that was an invasion. When the Germans planned to enact mass immigration into Slavic countries after the war, that was an invasion as well. When the communist countries of China and Russia imported their people into tibet and eastern European countries respectively, that was an invasion. And yes, when the early American settlers moved west, even when they intended to treat the natives humanely and decently, it did not change the fact it was an invasion. When Spanish-speaking people mass migrate into America, changing the culture, language, customs, and ethnic makeup of the country that is an invasion too.
No people should be denied the right to defend their home, no matter who they took it from