In the most recent “Atlantic,” James Fallows examines a foreign policy conundrum in a piece called “China’s Great Leap Backward.” Fallows, who saw the rise of China as a big story many years ago, relocated his family there for several years, learned the language and became a useful guide to the Middle Kingdom’s evolution.

He reminds us that, after Mao, China little by little became more capitalist, more open, more entwined with global networks of trade, communication and science, less insular, less repressive. But. It has begun to backslide, becoming noticeably less progressive that five or ten years ago.

It is usual to attribute the reversal to the arrival of Xi Jinping whose rule has featured a Maoist cult of personality, but Fallows maintains that substantive changes began before Xi and have included a crackdown on dissent, a greater military aggressiveness, a stricter control of information and less openness to Western business, cooperation and ideas.

The open question is whether the regression will outlive Xi’s tenure. It matters a great deal since the 21st Century is likely to be dominated by the relationship of the United States and China, as the world’s two largest economies.

The TPP trade deal that Donald Trump has promised to scuttle was designed in part to align China’s neighbors with the United States and prevent China from achieving complete regional dominion. Abandoning it may hasten the day when most of Asia is under the thumb of the 800-pound panda next door.

China’s road ahead is not easy. The increasingly repressive and kleptocratic party has remained in power by promising the masses a rising standard of living in exchange for limits on personal and political freedom. But as it becomes harder to maintain economic progress that lifts more Chinese out of poverty, tens of millions are likely to question an increasingly one-sided bargain.

China experts believe that in the long run the country will have no choice but to yield to the logic of globalization which dictates more openness, technological and scientific networking and entrepreneurial cooperation, not centralization and repression. But getting there may not be half the fun and will require delicacy and deftness on both sides.

And here we come to the present crux of the matter. For the next few years at least this tricky pas de deux is going to be executed by Xi and Trump, and the image that immediately springs to mind is of two scorpions in a bottle.

A business executive with considerable experience in dealing with China is quoted by Fallows as describing Xi as “a weak man who wants to look strong.” And it is suggested that the “the more grumbling he hears about his ongoing crackdown, the more ‘decisively’ he is likely to act.”

That would be alarming enough by itself, but on our side we are about to have a president who might be described in rather similar terms. That is, someone whose vanity or insecurity also prompts him to overreact, to boast and bully. They seem like a pair unlikely to play nicely together. Yet, as Fallows warns, the two powers are now entangled in complex ways — economically, scientifically, environmentally — so that “almost any measure that would ‘punish’ China” for bad behavior “would also damage the United States.”

And as a Jeffrey Goldberg interview with Henry Kissinger in the same “Atlantic” notes, when a rising power and an established power clash, a circumstance described by historians as the “Thucydides Trap,” the result can be cataclysmic. Consider the case of Athens and Sparta or the events following a peripheral assassination in 1914. In such cases each side may misstep or overreach and both sides can be destroyed.

Could a similar fatal folly occur between East and West today? Fallows warns that there is presently brewing in China a toxic combination of insecurity and aggression, but the president elect exploited similar fear and ire to achieve victory.

One can only hope that in both regimes some advisors with cooler heads will be whispering in the ears of their bellicose leaders. Trump’s NSC pick was not encouraging and his havering over Secretary of State, and some of the candidates proposed, is also disquieting.