1. Introduction

The People’s Republic of China and the Russian Federation established a strategic partnership of coordination in 1996, signed the Treaty of Good-Neighborliness and Friendly Cooperation Between China and Russian in 2001, established a comprehensive strategic partnership of coordination in 2011, and upgraded to a comprehensive strategic partnership of coordination in the new era between China and Russia in 2019. In 2021, the Treaty of Good-Neighborliness and Friendly Cooperation Between China and Russian was extended. The Russo-Ukrainian war broke out in 2022. Over the past three years since the outbreak of the war, China Russia cooperation is still deepening.

Some commentators have argued that the relationship between China and Russia has reached a “quasi-alliance” or even a “de facto alliance” [1]. This article disagrees with this assertion, but argues that most alliance theories in international politics are logically applicable to analysing non-alliance international cooperation, as long as they do not include clear alliance commitment as an element. This article will draw on realist alliance theory to analyse the changing characteristics and strategic logic of Sino-Russian cooperation in the context of the Russo-Ukrainian war. This study attempts to reveal the essence and potential risks of deepening Sino-Russian cooperation and expand the existing theoretical framework for understanding contemporary major power cooperation.

2. Theoretical framework and analytical perspective

Realist alliance theory, citing power and national interests as motivations, argues that power is both the means and the end for states to form alliances. Hans J. Morgenthau, in his book Politics Among Nations, emphasized that alliances are tools for sovereign states to safeguard their interests through checks and balances of power; the fundamental motivation for states to form alliances is to counter a stronger power, particularly to prevent the emergence of hegemony [2]. Kenneth Waltz, analysing alliances from an architectural perspective, also argues that states in anarchy will respond to threats through external checks and balances, namely, by forming alliances [3]. Glenn Snyder, in his book Alliance Politics, proposed the alliance dilemma theory, arguing that alliance members constantly face two conflicting fears, namely the fear of abandonment and the fear of entrapment [4]. The parts of these traditional theories based on clear alliance obligations are obviously not applicable to China-Russia relations, but the parts based solely on power and national interests are completely applicable, because achieving a balance of power and promoting national interests are also the motivations for China-Russia cooperation.

3. The promoting mechanism of the Russo-Ukrainian war on Sino-Russian cooperation

3.1. Increased strategic demands under the logic of power balance

The outbreak of Russia-Ukraine war marked a complete break between Russia and the West. Even if the war ends within a few years, long-term confrontation remains highly likely. For Russia, the deterioration of relations with Europe and the United States has elevated the importance of relations with China. Russia will not easily accept defeat, nor does it want a war to end in a draw while it still holds the initiative on the battlefield. Europe, on the other hand, harbours a deep fear of appeasement, and it is also difficult for the United States to unilaterally lift sanctions on Russia, which means abandoning all its allies: The two sides have nothing to be negotiated, and Russia’s diplomatic space has been severely compressed. Consequently, relations with non-Western powers, particularly China and India, have become crucial for Russia to break its diplomatic isolation.

The Concept of Foreign Policy of the Russian Federation in the 2023 edition reflects this strategic reorientation: China and India are ranked third, only behind the Commonwealth of Independent States (CIS) and the Arctic, while Europe and the Anglo-American region are ranked last. Furthermore, in the relevant chapter, content related to China precedes and significantly outnumbers that related to India [5]. Considering that the CIS and Arctic regions are, to a certain extent, internal regions for Russia, it can be argued that Russia has already considered relation with China its most important external relation. In addition, in his 2023 speech at Belt and Road Forum, President Vladimir Putin highly praised the initiative as aligned with Russia’s own vision, while making no reference to cooperation with Europe [6].

On a practical level, the combined power of the United States and its allies far outweigh that of Russia, especially in the economic sphere. Faced with war, sanctions, and isolation, Russia urgently needs Chinese cooperation to mitigate losses and counterbalance Western pressure. Bilateral trade has expanded rapidly: it exceeded $190 billion in 2022, a year-on-year increase of 29.3%, and it reached $240.1 billion in 2023, up 26.3% [7, 8]. This has significantly reduced the losses from Western sanctions. In terms of defence, the frequency, scale, and combat effectiveness of Sino-Russian joint military operations have increased significantly. Joint naval and air force strategic patrols have become regularized, involving patrols passing sensitive areas such as the East China Sea, the Sea of Japan, and international waters near Alaska. This has also given Russia greater confidence in responding to pressure in Far East as it stuck in the quagmire of Ukrainian war.

For China, Russia is its largest neighbour. Developing friendly relations with Russia is crucial to maintaining China’s stable geopolitical environment and has been a consistent choice of it since the collapse of the Soviet Union. China’s increasingly intensified competition with the United States since 2016 has made it even more imperative for it to unite with other powers to counterbalance the United States, so naturally, it will not refuse to deepen cooperation with Russia.

3.2. Reinterpreting the alliance dilemma in major-power relations

Snyder’s “alliance dilemma” highlights two persistent fears among allies: abandonment and entrapment . Although China and Russia are not formal allies, a modified version of this framework remains useful for analyzing great-power cooperation. Abandonment in major-power relations refers less to alliance commitments than to diplomatic realignment that reshapes the balance of the power. A prime example is the normalization of Sino-U.S. relations in the 1970s, which significantly worsened the Soviet Union’s international position despite the preexisting tensions with China and U.S. Entrapment, meanwhile, in great power relations stems from the globalization and the global reach of great powers’ economic interests, as well as their political and ideological influence: the escalation of one great power’s conflicts can impose losses on another with which it collaborates closely.

For China, the war has, to a certain extent, reduced fears of abandonment. Since the 21st century, nearly every U.S. administration has been obsessed with the idea of aligning Russia to contain China [9]. Although President Donald Trump openly characterized China and Russia as competitors in his first presidency, historical frictions between the two countries, the lessons of the Sino-Soviet rupture, domestic Chinese nationalism, and the asymmetric risks inherent in bilateral cooperation (discussed later) continue to constrain the development of Sino-Russian cooperation. The outbreak of the war, however, has eliminated the possibility that Russia joined forces with the United States to contain China, and made Russia lacked the ability to bear the consequences of abandoning China on its own. Therefore, China no longer needs to worry about Russia’s “betrayal,” and its fear of being “abandoned” in major power relations has been largely eliminated.

3.3. Opening of structural space for cooperation

Then war has greatly constrained Russia’s ability to sustain dominance in its traditional spheres of influence, creating structural space for deeper China-Russia cooperation. Central Asian countries, previously heavily influenced by Russia, have accelerated their implementation of a “diverse and balanced diplomacy,” engaging more actively with other major powers, including China. In May 2023, Central Asian countries and China held the inaugural China-Central Asia Summit, where all parties agreed to strengthen cooperation in the economic, trade, political, security, and cultural sectors. Russia’s stance on the China-Kyrgyzstan-Uzbekistan railway also shifted: while long opposed due to concerns about losing its transit monopoly, Moscow has since shown greater tolerance, refraining from stronger objections at the Collective Security Treaty Organization summit.

Another typical example is the establishment of a joint working group to develop the Northern Sea Route. For a long time, while encouraging Chinese ships to use the route and welcoming Chinese investment, Russia has refrained from collaborating with the Chinese government on overall development planning because it feared that China’s superior economic power would undermine its dominance over the route’s development. However, during Chinese president Xi Jinping’s visit to Russia in March 2023, Putin announced that the two countries would establish a joint working group to strengthen communication. After over a year of negotiations, in May 2024, a joint statement confirmed the establishment and future objectives of the joint working group. These developments indicate that Russia is, at least temporarily, accepting the weakening of its leading role in its traditional sphere of influence [10].

4. The constraining mechanism of the Russo-Ukrainian war on Sino-Russian cooperation

4.1. Increasing asymmetric risks

4.1.1. Russia’s asymmetric risks

China holds a significant economic advantage over Russia. In their bilateral trade, Russia primarily exports raw materials like cereal and energy-related minerals, while China’s focus is on manufactured goods. This structural asymmetry increases Russia’s economic dependence on China, creating potential vulnerability. Since the outbreak of the war, this dependence has intensified. For example, trade settlements are mainly conducted in Chinese yuan, and the imbalance between primary products and manufactured goods widened [11]. In 2023, China’s automobile exports to Russia reached 900,000 units, accounting for 92% of Russia’s vehicle imports [12, 13]. Chinese mobile phones, laptops, and other electronic products also saw a significant increase in their market share in Russia, while raw materials for energy accounted for 70% of Russia’s total exports to China [14]. On the other side, constrained by numerous sanctions and diplomatic isolation, Russia, apart from China, has no other country with abundant industrial strength as an option to fill the market gap left by Western withdrawal. While Russian energy and other products are important to China, no Russian product is completely irreplaceable. In other words, Russia is increasingly economically dependent on China, but China is not dependent on Russia.

In the political and diplomatic sphere, although China has offered Russia considerable support, such as consecutively abstained on several UN Security Council resolutions concerning Ukraine in March and April 2022 to refuse to label Russia an aggressor, differences remain. On the crucial issue of sovereignty in eastern Ukraine, China has never recognized the referendum results and has maintained open channels of dialogue with Europe and the U.S., while Russia risks deepening diplomatic isolation.

4.1.2. China’s asymmetric risks

China values a degree of stability in the current international system, while Russia has grown highly risk tolerant, seeking upheaval [15]. Before the war, this risk was relatively symmetrical. However, after the outbreak of the war, Russia was already locked in a fierce confrontation with the West, leaving no room for escalation in sanctions. Even if its diplomacy were further isolated or even contained, the marginal losses would be minimal. However, China did not want to be drawn into a full-scale confrontation with the West, especially Europe [16]. In the defence and security realm, it was important for China to prevent territorial disputes from escalating and the Taiwan issue from becoming internationalized. In the economic realm, secondary sanctions imposed due to trade with Russia also have created difficulties for many Chinese companies [11]. China has no special geopolitical interests to protect in Eastern Europe, where is thousands of miles away from it. The Russo-Ukrainian war has heightened the possibility of China being drawn into the conflict, suffering losses for Russia’s geopolitical interests.

4.2. Interference from third variables

The Russo-Ukrainian war has rapidly warmed relations between Russia and North Korea. Russia has provided substantial economic and technological assistance to North Korea, while North Korea has supplied weapons and equipment to Russia and dispatched troops to Russia for the war, which has sparked China’s concern. The formation of a Russo-North Korean alliance could lead the United States and its allies to strengthen their military presence in Northeast Asia, exacerbating defence pressure on China. Moreover, North Korea is the only country with which China still maintains legal military alliance obligations. If North Korea, supported by Russia, adopts riskier international strategies, China faces the real risk of entrapment, as Snyder suggests. Furthermore, given that, in history, external interventions in the Korean Peninsula would always elicit strong reactions from China, and given that China’s current political influence on the peninsula is significantly limited compared to its historical levels, deepening Russo-North Korean cooperation could mean greater uncertainty in Sino-Russian relations [17].

5. Conclusion

This paper selects, modifies, and employs realist alliance theory to dissect what promoting and constraining mechanism the Russia-Ukraine war created for Sino-Russian cooperation. It argues that the war limited and weakened Russia’s power, and thus created several incentives for the deepening Sino-Russian cooperation: Russia’s strategic predicament, China’s reduced fear of abandonment, and Moscow’s temporary retreat from its sphere of influence. The result has been record trade volumes, regularised joint patrols and cooperated projects in Central Asia and the Arctic.

Yet the same crisis has also magnified structural asymmetries. Economically, Russia is in the risk of sliding into the commercial and financial dependency on China that is reinforced by yuan-denominated settlements and the great advantage Chinese brands now enjoy in Russian markets. Politically, Beijing’s calibrated neutrality on Ukrainian sovereignty preserves its negotiating channel with the West, while Moscow’s diplomatic isolation leaves it with little leverage to contest Chinese terms. Militarily, the entanglement of Russia and North Korea risks rekindling great-power competition on the Korean Peninsula, potentially entrapping China in a conflict it does not seek.

Looking forward, the durability of the partnership will hinge on three variables: the battlefield outcome and residual power of Russia, the degree of U.S.–China rivalry, and China’s capacity to keep its Russian alignment below the threshold that triggers secondary sanctions. Should Russia emerge from the war with considerable power maintained, it may resist further subordination, causing cooperation to plateau. Conversely, a protracted quagmire or a sudden collapse of Russian forces would deepen Moscow’s dependence but simultaneously raise Beijing’s entrapment risk, intensifying Chinese caution. In either scenario, the paper concludes that a formal alliance remains improbable; The deepening of Sino-Russian cooperation following the outbreak of the Russo-Ukrainian war was a pragmatic, crisis-driven strategic choice, which, out of the region of publicity, is not “No limits.”