In fact, this long stability in Europe traces its roots to a free trade agreement the Schuman Declaration, leading to the European Coal and Steel Community, which later becomes the European Union.
Future peace may be. An interesting quote from Lee Kuan Yew (From Third World to First, p. 534):
"October, 1985. […] During my official visit, I was given the honour of addressing a joint session of the US Congress. […] I spoke on an issue then at the top of the American agenda - protectionism to safeguard jobs and check growing US trade deficits with newly emerging economies of East Asia. In 20 minutes, I described how the issue of free trade was really the question of war or peace for the world.
Nations wax and wane. I argued that if a nation on the rise, with an excess of energy, was not allowed to export its goods and services, its only alternative would be to expand and capture territory, incorporate the population and integrate it to make for a bigger economic unit.
That was why nations had empire which they controlled as one trading bloc. It was a time-honoured way for growth. The world had moved away from that after the end of World War II in 1945. GATT, the IMF, the World Bank and new rules made possible a prosperous and dynamic Germany in spite of large numbers of Germans returning from the East into a shrunken land area
So also with the Japanese, who had to leave Korea, China, Taiwan and Southeast Asia and be packed into a few Japanese islands. The Germans and the Japanese were able to stay within their boundaries and grow through trade and investments. They cooperated and competed with other nations and were able to prosper and flourish without wars.
But if trade in goods and services was blocked, then China would revert to its historical solution of small warring states conquering one another to gain control of more territory and people until they become one colossal continental empire. This tight, logical exposition may have convinced the legislators intellectually, but many found it emotionally difficult to accept."
World Wars were about ... Darwinism! Really. The German aristocrats thought that they should rule, because they were more fit. They all had a copy of Origin of the Species, read it and discussed its implications to nationalism at length. Their speeches were all about it.
Think of it - a lonely academic invents/discovers something, and 50 million people die over it. No, not talking about nuclear fission.
For the record, "survival of the fittest" has nothing to do with Darwinism. It was an expression coined by Herbert Spencer, contrast to the more neutral "descent with modification".
The Nazi approach was markedly different. They borrowed a lot from Lamarckism, Malthusianism and pan-Germanic mysticism, not necessarily just flawed, naturalistically fallacious interpretations of Darwinism. Eugenics, particularly, was largely started by Francis Galton.
Yet Darwin himself coined 'natural selection'. It was the leap from 'natural' to the human realm that German Aristocracy made, and fed nationalism to the point WWI was inevitable.
Which is funny because eugenics is fundamentally a form of artificial selection, much like the one practiced agriculturally for millennia. You're trying so hard to indict Darwin on this, when virtually all of Social Darwinism is unrelated to him.
You're not being descriptive. You're trying to equate a positive body of theory (Darwinian evolution) as necessarily implying a syncretic, normative body of theory (Social Darwinism, which varies from laissez-faire to collectivist interpretations, largely because most of it has scantly to do with actual Darwinism).
In other words, you're committing a naturalistic fallacy. It should also be noted that much of "Social Darwinism" is actually quite old, going back to Plato's endorsement of selective, rationed breeding in The Republic.
