Borders move. That’s not news in most of the world. Indeed, in Eastern Europe the maps might as well come with expiration dates; they just don’t last that long. Many of the boundary changes around the world are the consequence of the rise and fall of great powers. Today’s Russia is one of those hegemons, and its edges are moving in real time. Zoom in, and one would conclude that Russia is expanding. It invaded part of Georgia in 2008, Crimea and the Donbas in 2014, and then attempted to take full control of Ukraine in 2022.

Zoom out, however, and an entirely different picture emerges. The Russian Empire arguably peaked in 1914 (in terms of landmass/percentage of world population) or, as the Soviet Union, in the late 1940s-50s (geopolitical sway, including the East European buffer states) or in the 1970s (economic share), depending on how you measure these things. It has been weakening and geographically contracting ever since, albeit with long plateau periods.

Russian demographics suggest further contraction ahead. The normal population replacement rate is 2.1 births per female; for Russia, the total fertility rate is currently just 1.4. That means that the population, currently around 145 million, is on its way to a forecast 136 million by mid-century. This downward trajectory explains, in small part, why Russia invaded Ukraine – for the 41 million (and now c. 38 million) Slavs living there. If one incorporates Belarus as a part of the Russian Federation, the numbers move up a bit (by nine million), but the trajectory remains the same. While much of the global north faces similar population pressure, Russia is unique in terms of its large landmass, low population density, and the geopolitical risks associated with a secular decline in numbers.

This longue-durée, rise-and-fall-of-empires framework suggests additional regions where Russian borders may recede in the future. They include not only the territories Russia is desperately clinging to in Ukraine and the Crimea, but also the non-contiguous forward military base of Kaliningrad. A simple look at the map raises questions about its future. And there are numerous other potential fracture points in the Caucasus and Central Asia, as well as the many originally non-Russian, distant and sparsely populated ethnic enclaves absorbed when Russia was expanding eastwards from the late-16th century through to the 19th.

Perhaps the most dramatic geographic risk is the potential loss of the one million square kilometres of Outer Manchuria that Russia took from China by treaties in 1858 and 1860. Consisting of the lands north of the River Amur and east of the River Ussuri, the territory is 50 per cent larger than the entirety of Ukraine. Known today as the southern portion of Russia’s Far East, the area now constitutes all or parts of modern Amur Oblast, Primorsky Krai, Khabarovsk Krai, and the Jewish Autonomous Oblast of Birobidzhan. While barely populated outside a handful of urban areas, those cities are significant: Vladivostok hosts the Russian Pacific fleet. Khabarovsk is the seat of Russia’s Eastern Military District. Russia makes military aircraft at a large facility in Komsomolsk-na-Amur. And Russia’s Trans-Siberian railway runs right through the region. In short, the loss of these territories would be a big deal.

The current population of the Russian side of the border with China is about four million, with a density of three per kilometre. The population has fallen by approximately 20 per cent since the end of the Soviet Union. In contrast, the main Chinese province facing Russia in the area has 30 million people and a density of 66 per kilometre. While not all of the Chinese are crowded on the banks of the Amur, the contrast is striking. Of the two cities that face one another, Chinese Heihe has 1.2 million residents while Russia’s Blagoveshchensk has a population of 240,000. Satellite maps tell a similar tale: often cultivated, if not crowded, land on the Chinese side, and largely pristine landscapes on the Russian side of the Amur for much of the 1,800 kilometres that separates the two countries.

Moreover, for many decades, Chinese leaders have made it clear that the treaties transferring the territories were highly ‘uneven’ and that China has not forgotten Russia’s landgrab. Whatever Russian diplomats might say, for the Chinese it remains an unresolved issue. In 1969, the two countries even went to war briefly over the border. Neither side has forgotten that.

Most contemporary observers would consider Russia’s loss of these lands to be very unlikely to happen. The historian, however, looks calmly at the situation and sees it as nearly inevitable. Geography may not be destiny. Biology (demographics) may not be destiny. Geopolitics (the advance and decline of great powers) may not be destiny. But if all three are pointing in the same direction…

There are numerous, significant reasons why the next map-change will not happen soon, but they have mostly to do with Chinese considerations, rather than Russia’s historical arc. Whether Russia can defy the weight of its history remains to be seen, but its current approach to prolonging great-power status does not appear to be working. And the notion that, in the digital age, the physical boundaries of hegemons are no longer as important as they used to be is partially true, but on the ground, beyond the salons where the digiterati hold sway, the lines in the sand still matter a lot.

Why raise this issue now? As of autumn 2025, there are no recent developments directly in regard to the border. All of the history and considerations discussed here are in the public domain. Why then? Well, Russia’s invasion of Ukraine in 2022 shifted the Overton Window dramatically in regard to its borders. Its tenuous control of Crimea and the Donbas highlight Russia’s border weakness, not its strength. Now the topic cannot be ignored – and China surely is not ignoring it.

Before we consider Russia’s long-term contraction, it’s important to note that its expansion was unlike that of the main European empires. These were moderately sized West European countries (small in the case of the Dutch), which developed large colonies in distant lands across the seas. Navies were important, and economic considerations were paramount. The territories were gathered up during the 16th through to the 19th centuries and then lost over the 19th and 20th centuries as the individual Great Powers declined.

The Russian Empire’s path was different. The Russian heartland in the north Eurasian plain was already large in the 16th century when the Moscow-based princes began expanding their territories, essentially in all directions. There were few geographic barriers to slow their advance. (Russia eventually developed a navy but it was not critical to its overland expansion.) Along the way, the Russians conquered,  cajoled, and co-opted a Tower of Babel that inhabited the lands they absorbed: Finns, Estonians, Latvians, Lithuanians, Baltic Germans, Poles, various Eastern and South-east European Slavs and non-Slavs, Tatars in Crimea, the great variety of ethnic groups in the Caucasus region, the even greater variety in Central Asia as Russian explorers pushed eastward, the smaller ethnic groups in Siberia and the Far North, and finally the various ethnic Chinese groupings encountered as Russian flags approached the Pacific Ocean. The former Soviet Union formally recognised over 100 different ethnic groups within its borders, many of them with their own administrative territories.

It is this multi-ethnic but land-contiguous structure that makes the Russian Empire distinctive, both in its creation and in its subsequent unravelling. In contrast to the seafaring peers of Western Europe, the earlier land-based empires of Rome in the West and the Mongol Empire throughout Eurasia are closer analogues. But perhaps the most recent and relevant example is the decline of the Ottoman Empire, an event within academic and even political memory that has left shifting and unstable borders to this day. The lines in the Middle Eastern sand (courtesy of Mr Sykes and Mr Picot in 1916), the borders of southeastern Europe, the small states of the Caucasus – all were formed or reshaped as the ‘sick man of Europe’ retreated in the 18th and 19th centuries and failed in the early 20th. The sobriquet was provided by none other than Tsar Nicholas I. What goes around comes around, as the new ‘sick man of Eurasia’ faces a similar prospect of contraction and instability. The fate of Russia’s lands bordering China serves as a test of this proposition.

Russia’s incorporation of the area north of the Amur and east of the Ussuri happened only in 1858 and 1860, but it had been a long time coming. Russian expansion into Siberia began officially in 1581 when Cossack hetman Ermak Timofeevich led a detachment across the Ural Mountains and defeated the forces of the Khanate of Sibir’. This marked the beginning of a systematic and rapid conquest that would carry Russian explorers to the Pacific Ocean by the middle of the 17th century. The initial motivation was substantially economic – the pursuit of valuable fur-bearing animals, especially sable.

The early Russian penetration into the Amur basin in the 1630s-50s met fierce resistance from the Manchu Empire (Qing Dynasty), which considered the lightly populated region part of its domain. The construction of a Russian fort at Albazin on the Amur became a flashpoint, leading to sieges in 1685 and 1686. These conflicts ultimately resulted in the Treaty of Nerchinsk (1689), which forced Russia to withdraw from the Amur basin and recognise Chinese sovereignty over the region, specifically the northern side of the watershed and all the territory further east of it. The Treaty of Nerchinsk lives on in the Chinese narrative as the correct one, properly demarcating where Russia ended and China began. In reviewing the subsequent treaties and border changes, the Chinese regularly hark back to 1689, to lines that endured without issue for nearly two centuries.

The appointment of Nikolay Muravyov as Governor-General of Eastern Siberia in 1847 marked a dramatic revival of Russian territorial ambitions in the Far East. Muravyov was a visionary expansionist who recognised that control of the Amur was essential if Russia were to achieve its ambition to make Russia a naval power in the Pacific. Between 1854 and 1858, Muravyov led a series of expeditions down the Amur, each one establishing a stronger Russian presence in the region. The expeditions coincided with China’s weakness during the Second Opium War (1856-60), when British and French forces had demonstrated their ability to penetrate deep into Chinese territory.

Simultaneously, the Taiping Rebellion (1850-64) was devastating the Chinese heartland. This massive civil war consumed enormous military and financial resources, killed millions, and effectively paralysed the central government’s ability to respond to external threats. It was under these circumstances that Muravyov presented his ultimatum for control of the northern territories. Given the threat of a second front if Russia’s demands were refused, the Chinese negotiators had little choice but to accept Muravyov’s terms.

The Treaty of Aigun, signed on 28 May 1858, established the River Amur as the boundary between Russia and China, transferring all territory north of the Amur to Russian control. This single agreement ceded approximately 600,000 square kilometres to Russia – an area larger than France. The sparsely populated area held a variety of local Tungusic tribes, the ruling Manchus, and a sprinkling of Han Chinese.

Two years later, the Convention of Peking further expanded Russian gains. Signed on 24-25 October 1860, this treaty awarded Russia an additional 400,000 square kilometres east of the Ussuri, including the entire Pacific coastline down to the Korean border. This territory included the site where Russia would soon establish Vladivostok (‘Ruler of the East’). The scale of these territorial losses was unprecedented in Chinese history. The combined area represented roughly 10 per cent of what would become modern China’s territory.

From the Chinese perspective, these treaties embodied everything objectionable about the ‘unequal treaty’ system imposed by foreign powers during China’s period of weakness. Unlike some other territorial losses that occurred gradually or through complex political processes, the Russian acquisitions were sudden, massive, and directly attributable to foreign military coercion. While Britain and France sought commercial privileges and treaty ports from China, Russia had seized vast amounts of actual territory.

The borders established by the treaties from 1858 and 1860 remain broadly in place today, more than 160 years later. But Russia’s encroachment on Chinese territory did not stop at the river’s edge. In the late 1890s, the weakening Qing government granted Russia a concession to build and manage the China Eastern Railway (CER) running east-west across northern Manchuria. It ultimately connected Chita, east of Lake Baikal, with the port of Vladivostok on the Pacific. That is, Russia’s original Trans-Siberian railway ran through China. (A parallel line solely on the Russian side of the border – north of the Amur – was completed only in 1916.) By the terms of another agreement from 1898, Russia was granted another railway concession south from Harbin to Port Arthur, at the base of the strategic Liaodong Peninsula. The railway also controlled coal mines, forests, steamship lines, industrial enterprises, power plants, and other businesses and territory throughout Manchuria. The expansive concession gave Russia practical control over much of Manchuria.

The Boxer Rebellion of 1900 provided Russia with the pretext for further involvement. In addition to slaughtering thousands of Chinese living on the Russian side of the Amur (around Blagoveshchensk), Russian forces numbering over 100,000 invaded Manchuria. Russia’s occupation lasted until they were replaced a few years later by the Japanese who had prevailed against an over-extended Russia in 1904-05. Even after that loss, Russia retained control of the railway and continued to influence developments in Manchuria as China devolved into warlordism and civil war following the failure of the Qing Dynasty in 1912.

Soon after the Bolshevik Revolution in 1917, an exuberant Soviet official, Lev Karakhan, the Deputy People’s Commissar for Foreign Affairs, stated that Soviet Russia would return to the Chinese people ‘all that had been taken from them by the Tsarist empire’ by the ‘Unequal Treaties’. Offered in the chaos of revolution and civil war, the offer became a dead letter when the increasingly stable Soviet Union of the 1920s neither needed nor particularly desired to give up what had been built up and acquired by Russia over the prior decades.

The Soviet Union did finally cede control of the railway in 1935 to the Japanese who had occupied Manchuria starting in 1931 and had created the puppet state of Manchukuo. But Russia’s absence lasted just one decade. In August 1945, the Soviets returned in force, kicked out the Japanese and occupied Manchuria for a second time. Although they formally withdrew troops from the area in 1946, the CER was not returned to Chinese control until 31 December 1952 – three years after the establishment of the People’s Republic of China. That is, for all but one decade from the mid-1890s through the early 1950s, Russia exerted de facto influence if not outright control of Manchuria. Russia might not see that as a problem, but China has surely not forgotten it.

While the Soviet Union eventually handed Manchuria back, the Chinese government has other reasons to bridle at Russia’s involvement in the area. That is because the Soviet Union at times backed the wrong horse in the race for control of China during the extended Civil War between the Nationalist Kuomintang and the Chinese Communists. Stalin initially advised Mao Zedong against seizing power after the Second World War because the Soviet Union had signed a Treaty of Friendship and Alliance with the Kuomintang in 1945. Stalin’s support for Chiang Kai-shek’s Nationalists was in exchange for continuing those concessions in Manchuria. To make matters worse, the Soviet Union treated Mao and the Chinese communists shabbily after their so-called brethren in ideological arms prevailed in 1949. Stalin viewed China as a potential rival rather than a genuine ally; he feared that a strong Mao might become ‘a second Tito’, defying Soviet authority.

The death of Stalin in 1953 created the first serious opportunity since the 19th century for China to raise the territorial question with Russia. The initial attempt came during a meeting between Mao Zedong and Soviet Premier Nikita Khrushchev in 1954, when Mao referred to the territories ‘stolen’ from China by tsarist Russia, explicitly mentioning the Treaties of Aigun and Peking. The Soviet response was unequivocally negative – Moscow refused even to acknowledge that these territories had been improperly acquired, let alone consider their return.

Mao’s most famous public statement on the territorial question came during a meeting with Japanese socialists on 11 August 1964. As recorded in various sources, Mao declared that ‘there are too many places occupied by the Soviet Union. About a hundred years ago, the area to the east of Lake Baikal became Russian territory and since then Vladivostok, Khabarovsk, Kamchatka, and other areas have been Soviet territory. We have not yet presented our account for this list’. This statement represented the highest-level Chinese objection to the border.

As relations between the two countries deteriorated in the 1960s, China regularly raised the issue of the annexed territories. While Beijing did not explicitly demand the return of the lost territories, it insisted that Moscow formally recognise the illegitimate nature of the seizures. At the first formal round of Sino-Soviet border negotiations in February 1964, the Chinese delegation insisted that any border settlement must begin with Soviet acknowledgment that the 19th-century treaties were ‘unequal’ and imposed upon China under duress. The Soviet delegation rejected this demand entirely, arguing that accepting the Chinese position would legitimise unlimited future territorial claims.

The military clash at Zhenbao (Damansky) Island in 1969 represented the violent culmination of these brewing disputes (as well as much broader conflicts between China and the Soviet Union). While the immediate trigger was control over insignificant and often-flooded river islands, the underlying issue was China’s rejection of the legitimacy of the entire border established by the 19th-century treaties. Subsequent rounds of border talks in the 1970s and 1980s made little progress on the fundamental question, but the end of the Cold War and collapse of the Soviet Union created new opportunities for border resolution. The 1991 Sino-Russian Border Agreement and subsequent protocols resolved numerous practical demarcation issues – such as middle of the river versus a bank – and reduced tensions along the frontier. However, these agreements avoided the larger issue of territorial claims.

In 2001, Russia and China signed a Treaty of Friendship that formally declared the ‘final resolution’ of border disputes between the two countries. Article 6 of the treaty states that both parties consider their common border to be definitively delimited and have no territorial claims against each other. From the Russian perspective, this treaty permanently settled the territorial question and precluded any future Chinese claims. (The agreement did permit the future resolution of minor issues, which were reflected in the transfer in 2008 of 337 square kilometres to China.)

While the 2001 Treaty suggested finality on the border issue, that may no longer be the case. In retrospect, Chinese acceptance of those terms can be seen as a tactical compromise because China’s broader strategic interests at the time required good relations with Russia. But the fundamental Chinese grievance – the legitimacy of territory taken through ‘unequal treaties’ – remained unaddressed. A quarter of a century later, China now has the realistic option of viewing the agreement as a pause in a territorial dispute rather than its genuine resolution. That is, Nerchinsk held, until it didn’t. Aigun and Peking have held, more or less, for almost two centuries, with Russia often in breach due to its prolonged involvement in Manchuria. More generally, treaties are observed until they are changed, abrogated, or ignored. For declining hegemons, they simply may become irrelevant.

Does any of this matter? Yes, it matters, for the simple reason that the Chinese leadership has not forgotten this history, considers it important, and will likely take advantage of the turned tables to reclaim its lost territories over time. China’s ‘Century of Humiliation’ has become fundamental to understanding modern Chinese nationalism and foreign policy. This narrative framework, which describes the period from the First Opium War (1839) to the establishment of the People’s Republic of China (1949) as an era of foreign exploitation, provides the ideological foundation for China’s quest for territorial integrity.

Within this narrative, the Russian territorial seizures occupy a unique position. Unlike the commercial concessions extracted by Western maritime powers, Russia’s acquisitions involved the permanent loss of sovereign Chinese territory on an enormous scale. While China has recovered Hong Kong (1997) and Macau (1999), and maintains claims to Taiwan, the territories lost to Russia remain under foreign control with no immediate prospect of recovery through existing diplomatic mechanisms. This creates a conspicuous gap in China’s current geopolitical narrative. Since becoming General Secretary of the Chinese Communist Party in 2012, Xi Jinping has emphasised that the Chinese Dream narrative includes territorial sovereignty. While official Chinese policy does not explicitly call for the recovery of this part of the Russian Far East, the conceptual framework Xi has established suggests that the lost lands remain on China’s agenda.

The idea of territorial recovery extends beyond elite politics to popular consciousness. Social media discussions in China frequently reference the territories lost to Russia, often using Chinese names like ‘Haishenwai’ for Vladivostok and ‘Boli’ for Khabarovsk. When Chinese internet users circumvent censorship to express territorial grievances, the Russian lands across the border feature prominently in their discussions. A 2024 comment on Weibo captured this sentiment: ‘According to history, Russia should return us Vladivostok and vast territory stolen 100-something years ago.’

The educational system reinforces these territorial grievances through historical curricula that emphasise China’s territorial losses during the Century of Humiliation. As early as 1952, the textbook A Short History of Modern China featured a map that labelled ‘Chinese Territories Taken by Imperialism’. Chinese maps published by official agencies continue to reflect these territorial claims in subtle but significant ways. In August 2023, China’s Ministry of Natural Resources published maps showing parts of the Russian Far East with their Chinese names.

While this history matters a lot, it would be foolish to ignore the fact that the disputed regions also contain substantial deposits of timber, oil, natural gas, gold and rare earth minerals. China already accounts for two thirds of foreign investment in the Russian Far East, primarily concentrated in energy and agricultural sectors. And the level of economic development on the two sides of the border is wildly uneven in favour of China.

There is also the obvious military and security considerations of Chinese control of the territories adjacent to North Korea. Access to additional Pacific coastline would also support China’s growing naval ambitions. Climate change considerations add urgency to these strategic calculations as Arctic ice melts and northern territories become more accessible.

Russia’s failed invasion of Ukraine in February 2022 fundamentally altered the strategic outlook for Russia and created the conditions that make the border issues once again relevant. Russia’s military, economic, and diplomatic weakening, combined with China’s increasing global influence, has created an unprecedented disparity in relative strength of the two powers.

From a historical deterministic perspective, this is a done deal. It is just a matter of lowering the Russian flag and running up the Chinese colours. But there are plenty of reasons that ceremony will not happen anytime soon. The most obvious is that China does not actually need the physical transfer of territory in any immediate sense. As much as the flag-raising ceremony would be welcome in Beijing, China can wait. It already dominates the area economically and will continue to do so. And it’s far from clear where the new ‘old’ boundaries might be. Nerchinsk was vague about the northern watershed of the Amur. At that time, the area was little understood or mapped. Current depictions of the northern reach of the Nerchinsk agreement are arbitrary.

Moreover, Russia’s failure in Ukraine has inadvertently made Russia a junior ally in China’s relationship with the West. It suits China to have Russia draining the attention and resources of the West in Ukraine. While China will eventually challenge 1858-60, there’s no need to do it now while Russia assists China’s geopolitical agenda. The status quo provides many of the economic and political benefits of territorial control without the risks and costs of a formal transfer.

And there would be costs. China’s current economic challenges, including slowing growth and demographic decline, will make territorial shifts less attractive than they might have appeared during periods of rapid economic expansion. In particular, China’s Heilongjiang Province bordering Russia is among the country’s least developed and also has sharply negative demographics.

Regional and global strategic considerations also constrain Chinese territorial ambitions. As messy as the border with Russia is, at least a river runs through it. China’s borders with India, the states of Central Asia, and Mongolia have even more contested histories and complicated presents. An arbitrary move in the north-east would ripple along China’s entire northern and western border. And, while Russia is weakening, it remains a formidable foe. Russia’s decline will need to progress further before revision of the borders would not result in a war between the two nuclear powers.

How and when does this end? That depends on many factors – notably Russia’s management of its decline and China’s stewardship of its ascent. Decades seem more likely than years for an actual transfer of land. In the meantime, Russia’s involvement in Manchuria from the 1890s through to the 1950s provides a potential path forward. The CER could happen in reverse, with China exercising varying levels of influence over the lands north of the Amur and east of the Ussuri. ‘Special Economic Zones’ like the CER concession could be created. Look also for long-term leases of agricultural and timber land. They might come with enclaves that would eventually feature extraterritoriality. Any or all of these developments could signal a gradual return to Nerchinsk, or at least a refutation of Aigun.

Can Russia’s leadership avert or at least defer the latter portion of a traditional hegemon’s trajectory? That is, what is the role of individual agency or even a self-proclaimed ‘great man’ in a rise-and-fall, deterministic framework? Vladimir Putin is keenly aware of his country’s history and is certainly trying to direct it, not just be carried along by it. Russia is pressing its expansive border bets, not only in Ukraine but also by posturing along the rest of its Western border. It’s not a bad near-term stratagem. NATO’s Article 5 rings hollow for the Baltics, especially when Russia still has the functioning forward military base of Kaliningrad behind NATO’s frontlines. But Kaliningrad is as much a liability as it is an asset for a declining power. And while sabre-rattling along the NATO border makes good domestic headlines, Russia is too stretched in Ukraine to carry out its threats of further expansion to the West.

Russia’s leadership is also well-aware of the country’s demographic crisis, and it has been very open about encouraging family formation. But there is no evidence that these efforts will change the country’s near-term trajectory. And launching a war that has already cost Russia approximately a million casualties would appear to be at cross purposes with generating a baby boom.

The economic outlook is similarly unpromising. While Russia is a large country, it is a small economy, about the size of Spain and Portugal combined. Its expansive geography and the ultra-low population density outside of European Russia make economic development there all the more difficult. Indeed, two decades ago, when Russia was more free-market oriented, two prominent Western analysts suggested that it needed to stop wasting scarce resources supporting the unproductive and ageing Soviet infrastructure in distant Siberia. Instead, they recommended it should economically ‘shrink’ closer to European Russia, where its return on investment would be higher. In the intervening period, the ‘stranded asset’ nature of those remote territories – Vladivostok is 6,500 kilometres away from Moscow – has only increased.

More generally, Russia has made little progress during the past 35 years in becoming less dependent on commodities and natural resources. If anything, the so-called ‘no limits’ friendship between China and Russia makes the latter even more dependent on natural resources, as there is little else that Russia produces that is of interest to China. The recently announced Power of Siberia 2 gas project is a good example. It is supposed to run thousands of kilometres from Western Siberia to China, if it is ever actually built.

For now, Russia has found itself in the exceptional situation of enjoying the unusual patronage of the White House, which may or may not have expired, and the more logical supportive vassalage of China, which persists. Are those advantages sufficient to hold back the historical forces at work, other than briefly? Once ancient Rome’s central power had weakened and its far-flung legions began withdrawing, the end was destined. The more loosely organised Mongol Empire quickly fractured into numerous khanates that eventually succumbed to their local populations and faded from history. The Ottoman retreat took place steadily over two centuries as the Sublime Porte failed to modernise, economically and militarily, at the same pace as the West.

Russia’s path will necessarily be unique, but with regard to the territory taken from China, a scene in the 1982 film Gandhi comes to mind: Gandhi, played by Ben Kingsley, informs the British that it is time for them to leave and that 100,000 British will no longer be able to control 350 million Indians. The scene was a fiction, but it memorably captures the essence of Russia’s current demographic and geopolitical challenge along its border with China.