Land possession is part of a long history in which the stronger Native American tribes displaced weaker ones. The Native Americans, too, subscribe to the conquest ethic. But what about the charge of genocide? In the two centuries after Columbus, the Native American population declined by 80%. But it wasn't due to warfare. Rather, as historian William McNeill points out, they contracted diseases, measles, typhus, smallpox, cholera and malaria, to which they had no immunities. Now, this is tragedy on a grand scale, but it's not genocide because genocide implies an intention to wipe out a people. Just a century and a half earlier, one-third of the population of Europe was wiped out by a series of bubonic and pneumonic plagues. Those plagues came from Asia, and the Europeans had no immunities. We don't call that genocide.