Well, we wanted them out of our way and we were going to do it no matter what it took. The fact that disease and inter-tribal fighting, much of it at our instigation, helped as we tried to achieve our goal of clearing them out of the way does not mean that the attempted extermination is no longer genocide.
In 1492 when Columbus got to the New World there were an estimated 20 million native americans in N. America. By 1888 when we "closed" our frontier, there were 280,000 left. In what is now Mexico, there were another 20 million reduced to 1.5 million by the same date. I lack stats for S. America but if we assume another 20 million and use the 1.5 million left in Mexico as our common remaineder, that means Western Culture reduced the native population of the hemisphere from approximately 60 million to 4.5 million. Hitler considered Andrew Jackson one of his heroes for removing the Cherokee and saw no differnce between our native americans and "his" jews. With good reason, he was simply trying to do what we did.
After all, examine the history books and see if you can come up with ANY difference between the American notion of Manifest Destiny or the articulations of the Monroe Doctrine or Teddy Roosevelt's "Corrolary" and Hitler's Liebensraum. I have never been able to do so. And the language and intent behind his corrolary and what is known as the Brezhnev doctrine are also, essentially indistinguishable one from another.
Tad
Patriotism: Supporting your country all the time and your government when it deserves it. M. Twain