Of course, Russia's Asian hinterland isn't really empty (and neither was Palestine). 

But Siberia is as resource-rich and people-poor as China is the opposite.

The weight of that logic scares the Kremlin.

Moscow recently restored the Imperial Arch in the Far Eastern frontier town of Blagoveshchensk, declaring: “The earth along the Amur was, is and always will be Russian.” 

But Russia's title to all of the land is only about 150 years old. 

And the sprawl of highrises in Heihe, the Chinese boomtown on the south bank of the Amur, right across from Blagoveshchensk, casts doubt on the “Always will be” part of the old czarist slogan.

Like love, a border is real only if both sides believe in it:

And on both sides of the Sino-Russian border, that belief is wavering.

Siberia – the Asian part of Russia, east of the Ural Mountains – is immense. 

It takes up three-quarters of Russia's land mass, the equivalent of the entire U.S. and India put together. 

It's hard to imagine such a vast area changing hands.

But like love, a border is real only if both sides believe in it.

And on both sides of the Sino-Russian border, that belief is wavering.

The border, all 2,738 miles of it, is the legacy of the Convention of Peking of 1860 and other unequal pacts between a strong, expanding Russia and a weakened China after the Second Opium War.

Other European powers similarly encroached upon China, but from the south. Hence the former British foothold in Hong Kong, for example.

The 1.35 billion Chinese people south of the border outnumber Russia's 144 million almost 10 to 1.

The discrepancy is even starker for Siberia on its own, home to barely 38 million people, and especially the border area, where only 6 million Russians face over 90 million Chinese.

With intermarriage, trade and investment across that border, Siberians have realized that, for better or for worse, Beijing is a lot closer than Moscow.

The vast expanses of Siberia would provide not just room for China's huddled masses, now squeezed into the coastal half of their country by the mountains and deserts of western China.

The land is already providing China, “The factory of the world,” with much of its raw materials, especially oil, gas and timber. Increasingly, Chinese-owned factories in Siberia churn out finished goods, as if the region already were a part of the Middle Kingdom's economy.

One day, China might want the globe to match the reality.

In fact, Beijing could use Russia's own strategy: hand out passports to sympathizers in contested areas, then move in militarily to "Protect its citizens." The Kremlin has tried that in Transnistria, Abkhazia, South Ossetia and most recently the Crimea, all formally part of other post-Soviet states, but controlled by Moscow.

If Beijing chose to take Siberia by force, the only way Moscow could stop them would be using nuclear weapons.

And now Russia's war in the Ukraine has changed the balance within their relationship anyway.

Russia is now most defiantly the junior dependent partner.

Is military is depleted and its economy isolated.

China is its only bulk-buy customer for the resources it needs to sell in order to finance its war effort in the Ukraine and prop up its domestic economy at home.

Without doing a thing Xi has ended up with little Vlad over a barrel,

So when president Xi kicks back in his office after a hard day thinking about how to crush Taiwan, his gaze might settle upon the oversized world map on his wall.

Xi may start to thinking to himself "Gee, it would be so much easier to just 'Liberate Siberia from the yoke of western imperialism' rather than take on the whole world over some pesky ideological unsound little island in the middle of nowhere."

As Xi and defence minister Wang crack another couple of Heinekens together, they might idlily start considering the benefits of looking North rather than East - Extra space to accommodate China's ever expanding population, all the gas and oil their country is ever going is to need in the future for free - and on one to stop them!'

And it gets better - Taking out Russia would make China a hero in the West, the EU and the Americans would say 'Thanks', Ukrainian's would say 'We love you' and Taiwanese would shut up, say nothing and quickly fade from the global mindset.

How good is that!