Even in the Preamble to the US Constitution, it was understood that a nation that was something to be preserved for one’s “posterity.”The Constitution says "secure the Blessings of Liberty to ourselves and our Posterity". It is reasonable to assume that this means for the descendants of the free citizens at the time.
When I searched the word “posterity” on Google, the first definition to pop up was telling: “all future generations of people.” The idea that “posterity” meant “the descendants of a person” was described as “archaic.” Still, Merriam-Webster refuses to get with the program and still defines “posterity” as primarily meaning “the offspring of one progenitor to the furthest generation.” I highly suspect that this is the sort of “posterity” that the Founding Fathers intended.
The cobwebbed wombs and the blank-shooting scrotums that currently rule Europe obviously have no personal genetic stake in what happens to Europe after they die. To them, the Europeans of the future will be “all future generations” that inhabit Europe, not the biological descendants of those who’ve inhabited Europe for dozens of millennia.It does appear that the future of Europe is being sold out by its childless leaders.
A continent ruled by the sterile and inhabited by those who’ve been brainwashed or demoralized into choosing sterility themselves will have no posterity in the classical sense. Instead, they will be overrun by people from alien cultures who may not have developed much in the way of technology or philosophy but who at least possess the genetic wisdom to be fertile.