I’ll let others describe the economic carnage President Donald Trump’s tariffs have already begun to wreak. I want to describe the damage they will do to the American psyche and the American soul. Trump is building walls. His trade policies obstruct not only the flow of goods but also the flow o f ideas, contacts, technology and friendships as well. His immigration policies do the same. He assaults the institutions and communities most involved in international exchange: scientific researchers, universities, the diplomatic corps, foreign aid agencies and international alliances like NATO. The essence of the Trump agenda might be: We don’t like those damn foreigners. The problem is that great nations throughout the history of Western civilization have been crossroads nations. They have been places where people from all over met, exchanged ideas and came up with new ones together. In his book “Cities in Civilization,” Peter Hall looked at the most innovative places down through the centuries: Athens in the fifth century B.C., Florence in the 15th century, Vienna from the late 18th century to the eve of World War I, New York from the late 19th century to the mid-20th century, the Bay Area later on. They were all meeting spots for people from different nations. Hall writes, “People meet, people talk, people listen to each other’s music and each other’s words, dance each other’s dances, take in each other’s thoughts. And so, by accidents of geography, sparks may be struck and something new come out of the encounter.” This, he continues, happens in junction points, places that encourage global interaction. Such places have common characteristics: They are unstuffy, un-classbound, nonhierarchical, informal. Economic innovation explodes, he writes, “in places with a rich network of import channels, which in turn provide channels for new ideas.” This used to be America. A crossroads nation, we attracted highly driven immigrants who wanted to be where the action was. We championed free trade. British colonialism and American internationalism made English the closest thing we have to a global language. This used to be our future. In a 2009 essay for Foreign Affairs called “America’s Edge,” Anne-Marie Slaughter argued that power in the 21st century would accrue to nations that put themselves in the center of networks, and that America was well suited to play that role. We have a diverse populace with global connections, alliances across two great oceans, the greatest universities with large foreign student bodies. All that is being damaged. But that’s not even my main concern. My main concern is over the spirit and values of the country. People’s psychologies are formed by the conditions that surround them. The conditions that Trump is creating are based on and nurture a security mindset: they’re threatening us; it’s a zero-sum, dog-eat-dog world; we need to protect, protect, protect. We need to build walls. Once again, the problem is that if you look at the cultures of societies at their peak, that is pretty much the opposite of the mentality you find. In, “Civilisation,” his own survey of the high points of Western history, art critic Kenneth Clark concluded that great periods are built on great confidence — a nation’s confidence in its laws and its capacities. That shared culture of confidence naturally infused people with social courage, a venturing spirit. Think, for example, of the kind of people who drive innovation and dynamism. What are they like? They put themselves in unfamiliar situations. They are enthusiastic about novelty. Journalist Adam Hochschild once wrote: “When I’m in a country radically different from my own, I notice much more. It is as if I’ve taken a mind-altering drug that allows me to see things I would normally miss. I feel much more alive.” They have diversive curiosity. Their interests and enthusiasms span many spheres. Nobel laureates are at least 22 times more likely than the average scientists to have a side hobby as a magician, actor, dancer or some other type of performer. They have social range, a wide variety of friends. In the decades before he published “On the Origin of Species,” Charles Darwin exchanged regular letters with at least 231 scientists in 13 different fields, as varied as economics and biology. They are able to combine disparate worldviews. Creativity often happens when somebody combines two galaxies of ideas. Pablo Picasso combined Western portraiture with African masks. Johannes Gutenberg combined woodblock engraving, coin-making and the wine press to create his printing press. They are driven toward continual growth. They seek to expand their interests and attachments, to engage in continual self-improvement. You can spot such people because they have gone through different chapters. Always learning, they have shifted their interests and worldviews over the years, torn down one way of making meaning and built up something new. Ralph Waldo Emerson was onto something when he wrote, “Not in his goals but in his transitions man is great.” There’s a name for the values and posture I’m describing here: cosmopolitanism. The cosmopolitan has roots in one town and one nation but treasures and learns from many other national streams. In a phrase I’ve used before, her life is a series of daring explorations from a secure base. Sometimes it seems like the 21st century has witnessed one attack after another upon cosmopolitanism — from 9/11 onward. Leader after leader appeals to fear of impurity and threat. This mean world vibe not only reduces contact between peoples, but it squelches the venturesomeness that has been America’s best defining trait. Trump called Wednesday Liberation Day, but Stagnation Day might be more like it. If America is still America, these tariffs will represent the turning point of the Trump presidency. People will be outraged by the useless economic pain they are causing; and, more subtly, revolted by the cowardly values they represent. David Brooks writes a column for the New York Times. Related Articles Suzanne Nossel: Remember when it was the right that got outraged over ‘banned words’? Thomas Friedman: I just saw the future. It was not in America David M. Drucker: Congress began ceding power to presidents long before Trump Barbara McQuade: Nationwide injunctions are a problem. Ending them isn’t the answer Thomas Friedman: What I heard this past week in China about our shared future ...read more read less