Of course following WWII Western Europe had one huge advantage amidst its devastation. It was still a relatively homogeneous set of societies. Nature and its hardwired bias and hatred aimed toward the “other” always works against multicultural countries like the United States.
It just goes to show that the founding fathers, based within one of the last major slave states, were over the top optimists when talking about building a great democracy upon such idealistic phrasing as “all men are created equal.”
This of course quickly broke down in a bloody civil war that killed 600,000 folks out of a population of only around 30 million. So, yes, we will likely continue to trip all over our attempts to keep from becoming a multicultural failed country. Alas, hate is the most powerful of unifying agents. In the case of America, hatred will continue to be unified against the forces of modernity.