Which countries did we colonize? We administered the Philippines, but we didn't send over thousands of families to be a ruling class. And literally in every corner of the world throughout history people have lost their land to other groups who were either numerically superior, technologically superior, or both. As for the Mexican-American War, we went into that war with less than 6000 troops. The Mexicans had a standing army of 700,000. They didn't like Texas becoming a state and they started that war. And paid dearly. And genocide? Most Native Americans who died after the Europeans landed did so from diseases the Europeans brought that they had no immunity for. If we were looking to kill them all then why are there reservations everywhere? You buy into the same tired liberal nonsense.