We live in rather unprecedented and previously-unseen times in human history. And not in a positive way.
It is my understanding that this is, most probably, the first time in the entire history of humanity where entire nations hate themselves, their own country, their own people, and their own culture, so much that they willingly and deliberately want to shun, diminish, smother and outright destroy them, and actively replace them with people and culture from distant foreign lands.
This is probably unprecedented in human history. I'm not aware of any nation in the past that has done this, or gone through a period of this. There might have been some rare individual cases, but so far I have not found any examples.
Of course there have always been individual people, sometimes even influential ones, who have hated their own country and their own culture. However, these have never succeeded in swaying the opinion of the ruling elite to such an extent as to make them actively try to destroy the country and its culture, and replace it with a foreign one.
Likewise there have always been quarreling factions within countries, with completely differing opinions and views on how the country should be run, and which struggle and fight against each other (too many times literally) for power and dominion. However, almost invariably their opinion is "this is how this nation should be run", not "this nation, its people and its culture must be destroyed and replaced with a foreign culture and foreign people".
Governments with a policy of self-hatred, an active policy of cultural replacement, of actively shunning the country's and the people's own culture and trying to replace it with a foreign completely different culture, and to large extents succeeding in it, and with the government explicitly and actively celebrating this cultural replacement, is unprecedented. Especially so in peace time.
Government after government, and politician after politician, is more and more openly expressing their satisfaction, even glee, that the native population of the country is getting smaller and smaller, and more and more smothered, and replaced with foreign cultures from distant lands. They exalt the virtues of the foreign cultures, and how it's a good thing if they become the majority in the country, with the country's own culture becoming a minority, and perhaps even dying off completely. Sweden, Germany, the United Kingdom, Canada, Belgium, France... the list goes on and on, and is ever expanding, with concrete examples of politicians openly expressing these opinions, and actively seeking to bring as many African and Middle-Eastern immigrants as possible. They are more and more openly expressing how the country doesn't belong to the native people, and how it's a good thing that the native people will soon become a minority in their own cities. They actively celebrate the fact that the native culture of the country is dying and replaced with a foreign culture.
It's a very strange form of reverse invasion: Rather than one country invading other countries, instead the country is actively and willingly seeking for foreign countries to invade itself, in peace time. It actively wants its own country to be occupied by foreign forces and cultures, and for the native people to be subjugated to those foreign people, and to support their occupation. Rather than one country spreading to other countries and replacing their cultures, it instead is actively seeking to replace its own culture with that of the invaders which it's inviting in.
Even if something similar to this has ever happened before in human history, it most certainly has never happened to this scale. If there is a similar example in history, it most certainly was confined to one single nation. Today, however, this madness is spreading like wildfire from country to country. Country after country is destroying itself, its own culture, its own people, its own economy, and its own safety. And this ideology, this sickness of the mind, is so virulent that there seems to be no end to it.
Is it any wonder that right-wing political parties are starting to gain popularity? When the people feel betrayed by their own government, a government that seems to be actively trying to destroy the country, its economy, its people, and its culture, they will turn to the political party that values these things and does not want them destroyed. That's the only option they have got.