There were a lot of raised eyebrows and quiet chuckles this month when President-elect Donald Trump invited President Xi Jinping to Washington for his inauguration. Foreign leaders don’t attend our inaugurations, of course, but I think Trump’s idea was actually a good one. Having just returned from a trip to China, I can tell you that if I were drawing a picture of relations between our two countries today, it would be two elephants looking at each other through a straw.

That is not good. Because suddenly the U.S. and China have a lot more to talk about than just trade and Taiwan — and who’s the undisputed heavyweight champion of the 21st century.

The world today faces three epochal challenges right now: runaway artificial intelligence, climate change and spreading disorder from collapsing states. The U.S. and China are the world’s A.I. superpowers. They are the world’s two leading carbon emitters. And they have the world’s two biggest naval forces, capable of projecting power globally. America and China are the only two powers, in other words, that together can offer any hope of managing superintelligence, superstorms and superempowered small groups of angry men in failed states — not to mention superviruses — at a time when the world has become superfused.

Which is why we need an updated Shanghai Communiqué, the document that set out parameters for normalizing U.S.-China relations when Richard Nixon went to China and met Mao Zedong in 1972. Right now, unfortunately, we are denormalizing. Our two countries are drifting farther and farther apart at all levels. In the three decades I have been visiting Beijing and Shanghai, I had never felt what I felt on this trip — as if I were the only American in China.

Of course I wasn’t, but the American accents you would usually hear at a big Shanghai train station or Beijing hotel lobby were notably absent. Chinese parents say that many families no longer want their kids to go to the U.S. for schooling, because they fear it’s becoming dangerous — the F.B.I. might follow them while they are in America, and their own government might suspect them when they return home. The same is now true for U.S. students in China. A professor in China who works with foreign students told me that some Americans don’t want to study there anymore for semesters abroad, in part because they don’t relish competing against superintense Chinese undergraduates and in part because, these days, having studied or worked in China can raise security suspicions with future potential U.S. employers.

True, underneath all the talk of the new China-U.S. cold war, there are still over 270,000 Chinese students studying in America, according to the U.S. Embassy in Beijing, but there are now only about 1,100 American college students studying in China. That is down from around 15,000 a decade ago — but up from a few hundred in 2022, not long after Covid peaked. If these trends continue, where will the next generation of Chinese-speaking American scholars and diplomats come from and, similarly, Chinese who will understand America?