Remember the Sino-Soviet threat that emerged after the communist takeover of China in 1949? Indeed, during the Korean War, the monolithic red blot covering Central Europe, spreading over Eurasia and including China was a scary sight.

But then Joseph Stalin died and the U.S.S.R. and China fell out. Mao Zedong had no wish to play second fiddle to or take orders from Moscow. Soon there were skirmishes along the border and the two communist giants found themselves on the brink of war – especially since Beijing had historic territorial claims on the Russian Far East and in Eastern Siberia.

Now things look very differently. Russia is no longer a superpower, whereas China has quickly become one. While the Vladimir Putin government is hoping to ally itself with this new, potent China, many in Russia express concern that their country is now playing second fiddle to its formidable neighbor, becoming too dependent on China economically. It is giving the Chinese too many concessions and is letting Chinese immigrants colonize large swaths of underpopulated territories north of the border. In the end China, could end up acquiring its former lands by stealth.

This scenario could come to pass if Russia is thrown into disarray when Putin’s regime comes to an end – either due to natural causes or by means of a coup – or even in a popular rising. However, this is starting to look less and less likely even after Putin. Russian elites have become entrenched and Western sanctions have worked to keeping them – and their money – tethered to Russia. Even more important, the Russian people are consolidating around the leadership – which is quite a bit different from the situation in the final years of the Soviet Union, when the government and its system elicited nothing but disgust and ridicule from a large proportion of the Soviet population.

Finally, open borders allow more active, ambitious, better educated, employable and freedom-loving Russians to leave the country. They now go abroad instead of fomenting discontent at home.

Russia’s national idea has always been territorial expansion. While the country has been considerably diminished in terms of territory and halved in terms of population, Putin is feeding Russia a set of familiar tropes: monarchy, Orthodox faith, collectivism, territorial gains, war, hostile encirclement by foreign powers, a set of common enemies and rebuilt national greatness. The country is readily buying this type of propaganda, even if it is complete and utter sham, or rather virtual reality.

The Russians who remain in the country are willing to suffer considerable economic privations for the sake of these empty symbols. They have tried democracy and capitalism, and then saw fool’s gold of oil wealth flash by, and now want to go back to a hybrid of the Russian Empire and the Soviet Union which the Putin regime is offering.

And in fact Russia has been scoring victories both in real wars and in asymmetrical warfare. It is returning to some of its sphere of influence in Africa and the Middle East and engaging in the old rivalry with the United States – albeit on a much reduced scale.

It could get worse – and the Sino-Russian relations hold a key to this more unpleasant future.

The world order is in flux. The “New World Order” declared by George H. W. Bush after the fall of the Berlin Wall is coming apart. The United States, the linchpin of the international political system throughout the post-World War II period, appears to be no longer willing or able to perform this role. Donald Trump was elected to shake things up, and he’s certainly reshaping America’s foreign policy, altering military and political alliances and shuffling the list of its friends and foes. The United States is not only withdrawing from an active global role but it is turning inward to focus on catastrophic internal divisions – which Trump systematically and deliberately deepens.

This is a situation that should in theory create an opportunity for China to emerge as the next world leader, supplanting the United States. It has the world’s second-largest economy valued at $12 trillion and the largest population. Its military is powerful and its commercial ties reach into Africa, Latin America and Central Asia. Faced with Trump’s protectionist threat, the European Union is now reaching out to Beijing to form a common front – against the United States.

However, for all its apparent prowess, China may be a proverbial colossus with feet of clay. China’s rise so far has been similar to that of Japan. Much like the fear of China today, in the 1980s a global takeover by Japan appeared to be a foregone conclusion. Japanese automakers, consumer electronics companies, hi-tech giants and banks looked poised to knock their American competitors out of the water and gradually broaden their reach around the world.

Today, those ideas seem ridiculous, whereas the Chinese threat appears to be real. But China is plagued by many of the same problems that proved fatal to Japan’s ambitions – and many of those problems are even worse in China’s case. They both have aging populations and, in China’s case, an overhang of boys in the one-child generation. Both nations are obsessive savers – which makes it difficult to overcome their export dependency; worse, when exports shrink, the tendency to save becomes exacerbated. They are major exporters of capital but their investments often turn into massive sand castles.

Neither nation has been able to innovate independently, relying on others to provide technology. Trump’s trade war has already exposed China’s vital dependency on US technology and consumer markets.

All this raises the risk that in China, too, will face a period of Japan-style intense growth would be followed by Japan-style open-ended stagnation. Moreover, problems in the economy present a danger of political upheavals given its ossified, inflexible, non-democratic and non-transparent system of government.

A period of rudderless – and leaderless – drift on the international arena would be tailor-made for a highly mobilized, determined and unscrupulous actor – such as Russia. There have been other periods in world history when ragtag armies scored considerable successes, overpowering and conquering considerably richer, more advanced and better organized countries.

Putin’s Russia is already inspiring fear and, for the first time since the fall of the Soviet Union, it is starting to gather allies and admirers. They are ranging from Viktor Orban’s Hungary to Matteo Salvini’s Italy. The danger is that Russia could take advantage of an uncertain situation in China, reviving the old alliance and once more taking on the Older Brother role. This would make the old Sino-Soviet alliance, which unleashed the Korean War and set up the Kim dynasty in North Korea, seem like child’s play.

It is still a far-fetched scenario, but as Washington turns its back on the global political and economic system it should be aware of the risks it will leave behind.