Thucydides, an Athenian, wrote the history of the war between the Peloponnesians and the Athenians, he began at the moment that it broke out, believing that it would be a great war, and more memorable than any that had preceded it.
People are less certain of their national identities or their place in the world. It starts looking different and disorienting. And there is no doubt that that has produced populist movements both from the left and from the right in many countries in Europe.