Over 10,000 Russian and Chinese troops are currently poised to launch a big joint exercise in the vast and largely arid plains of China's Ningxia region, adjacent to the Yellow River.

The move comes as both countries face a deteriorating relationship with the United States, a fact which both sides appear eager to underline: As Chinese Defence Ministry spokesman Wu Qian put it last week, the military manoeuvres aim "to consolidate and develop a comprehensive strategic partnership of cooperation between China and Russia".

In theory, the latest exercise is no big deal; China and Russia have staged much bigger military manoeuvres in the past and some of them rehearsed far more menacing military operations than the ones currently contemplated.

Still, the latest exercise comes at a particularly sensitive time, just as debates are raging in many capitals about the significance of this growing Sino-Russian partnership, and about what Western governments can do to keep Beijing and Moscow away from creating a fully fledged alliance.

US President Joe Biden spent much of his extensive June European tour urging America's allies to close ranks against what he sees as a growing threat from China and Russia.

The recent concessions which the Biden administration made in accepting a controversial pipeline project aimed at delivering Russian natural gas to the heart of Europe were also presented as a gesture by Washington to tempt Russia away from its association with China.

And top European leaders such as French President Emmanuel Macron frequently justify appeals for friendlier relations with Russia with the need to avoid the creation of a "Sino-Russian axis".

But in reality, many of the fears articulated by Western politicians and strategic commentators both underestimate the significant obstacles to the emergence of a real Russia-China military alliance and overestimate what the two countries either want or plan to do. In short, the "dragon-bear alliance" is unlikely to emerge any time soon.

It is worth recalling that, for at least half of the Cold War period, China and Russia (in the guise of the Soviet Union) were sworn enemies that periodically came to blows and occasionally contemplated an all-out war.

China's state-controlled media - and the officially approved history taught in China - now likes to concentrate on Moscow's help with China's industrialisation during the 1950s, but this story conveniently overlooks decades during which the two neighbours traded insults, or the period of the 1980s when US intelligence agencies were using Chinese territory to eavesdrop on Soviet military activities.

Relations between Moscow and Beijing began to normalise after the collapse of the Soviet Union but, even then, only very slowly and hesitantly.

Chinese contempt

To start with, Chinese officials could barely disguise their contempt for Russian politicians who, as seen from Beijing, were simply far too weak or cowardly to keep their country together.

The most serious challenge to the Communist Party of China - the Tiananmen Square protest movement of 1989 - came as a direct outgrowth of and drew inspiration from the collapse of the communists in the Soviet Union. And the fact that China's leaders stuck together and did not flinch from using force to crush their opponents has long been presented at Chinese party schools as the difference between the superior Chinese version of communist rule and the failed Soviet model.

It was, therefore, initially difficult for Beijing to establish a close relationship with a country like Russia, which the Chinese presented as a classic example of failed governance.

And the Russia which emerged from the Soviet Union's rubble was not particularly interested in China either. During much of the 1990s, Russia's leaders still believed in their country's integration into European and wider Western structures.

And, just as their predecessors had done over many previous centuries, Russia's leaders initially dismissed the possibility of their country's tilt towards China in largely racially derogatory terms, as an option supposedly beneath Russia's "European vocation".

As a result, a comprehensive friendship treaty between Russia and China was signed only in 2001, a full decade after the Soviet Union collapsed.

Of course, all this changed, as Russia's dreams of becoming a "normal" Western state gave way to resentment against the West in general and the US in particular, and as Chinese relations with the US took an increasingly antagonistic turn.

Complementary roles

In theory, Russia and China complement each other well now, and in every critical area. Russia is a vast country with a relatively small population; China's territory is much smaller, but it has a vast workforce. Russia is primarily an exporter of oil, gas, and other raw materials; China is the world's biggest single consumer of all these commodities. Better still, Russia's top manufactured exports consist of weapons, and China is keen to buy them.

Then there is the political context. Both countries resent America's global reach, and both are subjected to various economic, financial and technological sanctions imposed by Washington.

Finally, both China and Russia lack formal alliance structures that can be mobilised to advance Beijing's or Moscow's interests in the way the US does for itself, so forging a bilateral link offers them opportunities they cannot find elsewhere.

Unsurprisingly, therefore, both sides are now effusive about each other. Russia is the country which Chinese President Xi Jinping visited most often, and Mr Vladimir Putin, his Russian counterpart, is without doubt Mr Xi's favourite foreign leader.

Both countries now appear ready to push their relationship further. In October last year, President Putin startled everyone by answering in public a question which he previously always avoided. Asked whether Russia should form an alliance with China, Mr Putin replied that he is "not going to rule it out".

And Beijing, which used to be equally tight-lipped about characterising its relationship with Russia as an alliance, is also suddenly prepared to discuss the possibility. "The more turbulent the world becomes, the more stable China-Russia relations should be," Chinese Foreign Minister Wang Yi told Mr Sergei Lavrov, his Russian counterpart, recently.

Nor is the messaging confined to words alone. For at the end of last year, Russian and Chinese fighter jets held what both countries refer to as "joint air strategic patrols" over the South China Sea and the waters off the east coast of the Korean peninsula, to the evident displeasure of both Japan and South Korea.

Still, much of this is a show, designed to attract the attention of other countries and warn off the US, rather than lay the foundation for a formal alliance.

Bilateral trade has more than doubled over the past decade, from around US$50 billion in 2011 to over US$100 billion (S$135 billion) today. Still, Russian oil and gas exporters turned to China only after the Ukrainian war of 2014, when Russia was subjected to an array of Western sanctions and was short of cash.

And despite the fast growth in Russian energy exports as well as the repeated professions of love between the two neighbours, the fact remains that Russia's sales of oil and gas to Europe remain three times higher in volume terms than the sales to China and, over the past year, that gap in Europe's favour has increased.

Furthermore, and notwithstanding all the diplomatic embraces, both sides are suspicious of each other.

Russia's leadership is acutely aware of its country's inferior economic status. When the Cold War ended in 1989, Russia's economy was double that of China; today, China's economy is six times larger than Russia's.

Russia may look to China as its salvation from Western sanctions and isolation. But for China, Russia is hardly a big export market; it ranks just above the Philippines, for instance, in the volume of Chinese exports, not the sort of comparison Moscow appreciates.

And despite all the joint military manoeuvres, the militaries of both countries view each other warily. The Chinese were startled by Russia's military operations in Ukraine back in 2014; China may have been the ultimate beneficiary from the growing confrontation between Russia and the West, but there is no question that Chinese military planners viewed Russia's Ukraine actions as unnecessarily risky.

Russian wariness

And there is little doubt that Russian military analysts are none too pleased by China's growing presence in Central Asia, a region which Russia regards as within its sphere of influence.

Furthermore, several recent statements from key Russian commentators indicate a growing debate in Moscow about the purpose of the country's security links with China.

Dr Dmitry Trenin, one of Russia's most astute observers with close links to Moscow's official thinking, recently wrote that "the fact that China is so much more powerful in economic terms than Russia should not make Moscow more pliable".

Instead, he warned, Russia needs to be more careful. "For Russia, developing further cooperation with China only makes sense if it does not lead to one-sided dependence on it. Becoming part of a Pax Sinica, China's sphere of influence, is absolutely unacceptable," he said.

Professor Alexander Lukin, who runs the Department of International Relations at the Higher School of Economics, one of Russia's top universities, also recently rejected the idea that his country is in a military alliance with China. Instead, he claimed that the relationship with Beijing is more akin to an "understanding", a delicately poised arrangement in which "Russia is still somewhat stronger militarily, while economically China is much more effective".

It's hard to tell whether Prof Lukin truly believes that the balanced relationship he described exists, or whether this is just his wishful thinking. Still, his description is hardly one which indicates Russian faith in the birth of a new and mighty military alliance.

'Horizontal escalation'

Despite all these caveats, Western military planners still need to take the Sino-Russian link seriously, if only for one reason: its potential to surprise and its ability to divert away Western resources.

If, for instance, there is a military incident between the US and China in Asia, Russia could engage in military incidents in Europe at the same time, thereby complicating the strategic calculations of Western governments.

This is something strategic experts refer to as "horizontal escalation", namely responding to an adversary by opening a new and unexpected challenge in a completely different region. And it is clearly something the China-Russia link has plenty of opportunities to deliver on, with the intention of confounding Washington's potential response in times of a crisis.

But that does not amount to a strategic game changer requiring a change in US strategy. So, at least for the moment, the Biden administration does not need to devote too much effort to trying to keep Russia and China apart.

For as Professor Michael McFaul, a noted Russia expert and former US ambassador to Moscow, recently put it, "trying to prise Russia away from China is a fool's errand", an exercise which requires more effort than is ever likely to produce advantages for the West.