Nationalism is a feeling, not an idea. It is the sense that every individual is just a small part of a larger community which is the organism that really matters in history. It is the belief that the culture attached to that community is better than anyone else’s, and must be protected at all costs. It ties the lives of individuals to a cause that is bigger than themselves. It can, and often does, serve as a substitute for religion, which largely serves the same purpose.
Because nationalism is not an idea, it cannot be rebutted with logical arguments–only results. The first half of the twentieth century provided us with those in spades. Politicians throughout the world consequently worked very hard after World War II to create institutions that would prevent nationalism from getting out of control again. Liberal democracy, the various institutions associated in one way or another with the UN, the EU, even international communism in its way–all of them were designed to restrain the worst excesses of nationalism. They have worked pretty well, on the whole; the world has become a more peaceful place, to the benefit of everyone.
But time passes, and people forget. Steve Bannon somehow views the thirties as being some sort of golden age. Trump’s “America First” mantra is a rejection of internationalist institutions. Revisionist states are on the prowl. The world is getting more dangerous.
Where are we going with this? American support of international institutions is vital if they are to survive in any meaningful way. If Biden wins, the Trump era will probably be viewed as an outlier in the long run. If Trump wins, heaven help us all.