Adversaries and the Future of Competition

Photo: SERGEI GUNEYEV/POOL/AFP via Getty Images

Photo: SERGEI GUNEYEV/POOL/AFP via Getty Images

This commentary is part of a report from the CSIS Defense and Security Department entitled War and the Modern Battlefield: Insights from Ukraine and the Middle East.

This chapter examines cooperation between China, Russia, Iran, and North Korea.1 It asks several questions: How has cooperation evolved between China, Russia, Iran, North Korea, and other actors, including during the Ukraine war? How might cooperation evolve over the next three to five years? What are the implications for modern warfare?

This chapter outlines three possible security arrangements between China, Russia, Iran, and North Korea: (1) weakening engagement, (2) deepening bilateral relations, or (3) a multilateral alliance. Under weakening engagement, cooperation between one or more of these axis members wanes because of divisions and diverging interests. There is greater infighting among countries and a decline in the overall degree of cooperation. Under deepening bilateral relations, cooperation between the axis countries increases in such areas as the defense industrial base, though cooperation remains largely bilateral. Under a multilateral alliance, axis countries establish multilateral arrangements that include higher levels of cooperation, such as a multilateral treaty or other agreement that commits three or more signers to collective assistance in case of external attack.

China, Russia, Iran, and North Korea are most likely headed toward deepening bilateral relations . . . which has significant implications for the future of warfare.

This chapter concludes that China, Russia, Iran, and North Korea are most likely headed toward deepening bilateral relations. This arrangement would involve axis countries increasing military and dual-use exports and imports, expanding the scale and scope of bilateral and, potentially, multilateral exercises and training, deepening defense industrial cooperation, establishing bilateral treaties or pacts that commit the signatories to greater military cooperation and even mutual defense in case of attack, and deploying soldiers to fight in the wars of other axis countries.

There are still likely to be areas of disagreement and tension between these countries, as well as limits to their cooperation. But the overall trend is likely to be greater cooperation, which has significant implications for the future of warfare. For example, closer cooperation increases the possibility of inter-theater military aid among axis countries in case of war and raises the prospect that two or more major wars could occur simultaneously in different theaters. It is prudent for such countries as the United States to be prepared to fight two wars at the same time, rather than focus on one region such as the Indo-Pacific.

The rest of this chapter is divided into three sections. The first provides an overview of lessons from Ukraine and the Middle East regarding axis cooperation. The second examines the possible evolution of the axis. And the third outlines possible indications and warnings to help gauge whether cooperation between axis countries is strengthening or weakening.

Lessons from Ukraine and Other Wars

Security cooperation between two or more powers is a routine occurrence in international politics. China, Russia, Iran, and North Korea see aspects of the Western-led liberal order as a set of rules designed to benefit the United States and its allies while forestalling potential rivals. In addition, these countries believe U.S. and allied efforts to promote democracy, support a free and independent press, maintain a free market, and encourage the free flow of ideas directly conflict with their goals of regime stability.2 All four powers are also revanchist. As the historian Philip Zelikow argued, they are “fundamentally revisionist powers. Their leaders regard themselves as men of destiny, with values and historical perspectives quite different from the consumerist or social metrics that suffuse much of the world.” He continued that they “all feel boxed in by extensions of American power they regard as fragile, though formidable in parts. All have long been preparing for a great reckoning.”3

In addition, each country has its own reasons for pursuing cooperation. China likely wants partners to help achieve what Chinese leader Xi Jinping called the “great rejuvenation of the Chinese nation.”4 China needs access to critical minerals, bases, ports, and markets. Russia has needed assistance following its February 2022 full-scale invasion of Ukraine to keep its economy afloat, energize its defense industrial base, and ensure it can continue waging war. Iran and North Korea both seek to circumvent international sanctions, are desperate for outside investment, and desire both great power diplomatic protection and military aid in the event of a conflict with the United States or their pro-U.S. neighbors, such as Israel and South Korea, respectively.

Beginning in 2022, China provided substantial aid to Russia’s full-scale war in Ukraine, including tooling machines, semiconductors, microelectronics for use in Russian weapons systems, spare parts, drones, gunpowder, and military contractors. Chinese companies such as Xiamen Limbach helped design and develop Russia’s Garpiya series long-range attack unmanned aircraft system, in collaboration with Russian defense firms like Joint Stock Company Aerospace Defense Concern Almaz-Antey.5 China also provided satellite imagery analysis and aid to improve Russian satellite and other space-based capabilities for use in Ukraine.6 Chinese companies even provided cotton cellulose, nitrocellulose, and critical ingredients for nitrocellulose (such as cotton pulp), which are explosive precursors that the Russian military uses to produce gunpowder, rocket propellants, and other explosives.7

This list of Chinese aid likely excludes many systems and components that are shipped clandestinely and whose status is not reported. China has apparently used cargo ships, trains, trucks, and aircraft to send material to Russia.8 Several Chinese-based companies, such as Poly Technologies, Fujian Nanan Baofeng Electronic Company, China Taly Aviation Technologies Corporation, Juhang Aviation Technology Shenzhen, Finder Technology Limited, Tulun International Holding Limited, and many others, have likely exported material.9 Although vital to Russia, some of the Chinese material, such as chips, is of low quality compared with more advanced chips from the United States, Europe, Japan, South Korea, and Taiwan.

Iran has exported drones to Russia, as well as artillery shells, ammunition, and short-range ballistic missiles.10 Russia and Iran have strengthened industrial base ties and set up production of Iranian drones—especially the Shahed-136—in Russia’s Tatarstan region.11 Russia has supplied Iran with Su-35 multirole fighter jets and other weapons systems, as well as aid to Iran’s space and missile programs.12 Finally, North Korea has provided artillery rounds (including 152 mm and 122 mm), multiple launch rocket systems, KN-23 and KN-24 solid-propellant short-range ballistic missiles, soldiers, and other defense materiel to Russia.13 Table 1.1 provides an overview of some types of military cooperation between China, Russia, Iran, and North Korea.

Seth G. Jones

Seth G. Jones

President, Defense and Security Department; Harold Brown Chair

Programs & Projects

Not all cooperation has centered on the Ukraine war. Chinese and Russian companies and agencies have also provided weapons components and intelligence (including satellite imagery) to Iran and the Houthis, an ally of Iran that conducted strikes against U.S. warships in the Red Sea and Israel.14

Despite these examples of cooperation, there have been some limitations. Chinese leaders have expressed concern about Russia’s warming military relations with an erratic North Korea, including the strengthening of Pyongyang’s missile capabilities.15 Beijing has generally been reluctant to help Pyongyang with its nuclear program.16 Iranian leaders have expressed dismay with Russia and China for their diplomatic positions in a spat between Iran and the United Arab Emirates over the sovereignty of islands in the Persian Gulf—including Greater Tunb, Lesser Tunb, and Abu Musa—which dominate the approach to the strategic Strait of Hormuz.17 During Iran and Israel’s 12-day war in June 2025, China, Russia, and North Korea did not provide substantial aid to Iran as Israel and the United States gained air dominance and struck targets across the country. China and Russia issued pro forma denunciations of U.S. actions, but they did not provide significant military assistance.

Future Evolution of the Axis

Several factors are likely to impact the type of security arrangement among the axis countries in the future. First is the degree of common threat. Since countries tend to increase cooperation to prevent stronger powers from dominating them, axis countries facing a growing external power or threat will likely increase security cooperation. The severity of the threat could be affected by the military power of an adversary country or alliance, including its offensive military capabilities; geographic proximity, since closer adversaries likely pose a greater threat; and the assessed intentions of the adversary country or alliance, which could vary from benign to malign intentions.18 Second is the level of ideological solidarity, including shared political, cultural, or other traits or interests.19 The more interests countries share in common, the likelier they are to want to cooperate.20 Third is domestic politics, including the preferences and decisions of leaders.21 Regime change—including the death of a leader—could impact the degree of cooperation and the type of security arrangement. Alternatively, leaders could develop stronger bonds that increase the prospect for cooperation.

Table 1.2 provides an overview of the three possible security arrangements: weakening engagement, deepening bilateral relations, and a multilateral alliance. These possibilities are not meant to be exhaustive but rather serve to illustrate plausible future security arrangements.

Weakening Engagement

In this scenario, bilateral relations between China, Russia, Iran, and North Korea become more tenuous, though axis countries might continue to cooperate in some form. This scenario assumes a weakening of bilateral security arrangements and declining levels of cooperation. Examples include decreasing exports and imports of military and dual-use items, as well as conducting joint exercises and training that are more symbolic than substantive. There are already periodic disagreements between the countries that could worsen over time.22

In sum, weakening engagement would include a general fraying of military and security ties between axis countries. Several factors could lead to such an outcome. First is a declining threat environment, which would reduce the need for aggregating power.23 The end of the war in Ukraine or between Israel and Iran (including Iranian-linked groups), a substantial weakening of NATO, or a significant decrease in defense spending among major powers in Europe or Asia could weaken the impetus for cooperation by decreasing the threat. A second factor is fraying common interests. Examples include growing divisions on such issues as territorial disputes (such as a flaring up of Sino-Soviet border disputes or the sovereignty of islands in the Persian Gulf), diplomatic détentes that create fissures, and even warming relations between some axis countries that threaten others (such as between Russia and North Korea, raising concerns in China). Third, domestic challenges could weaken bilateral relations. The death or removal of a leader—including Xi Jinping, Russian President Vladimir Putin, Iranian Supreme Leader Ayatollah Ali Khamenei, or North Korean leader Kim Jong Un—could lead to a shift in foreign policy and a decision to decrease axis cooperation.

The anchor of the relationship is likely Beijing because of its size and military, economic, and technological power, though relations between Beijing and Moscow are likely the core of the axis.

Deepening Bilateral Relations

Under deepening bilateral relations, cooperation between axis countries increases. The anchor of the relationship is likely Beijing because of its size and military, economic, and technological power, though relations between Beijing and Moscow are likely the core of the axis. Overall, axis countries continue to develop closer bilateral ties in defense industrial production, including emerging technologies that have significant military capability, such as AI and quantum computing. A deepening coalition could include growing cooperation in several areas.

Arms exports and imports among axis countries continue under deepening bilateral relations, but they increase in scale and scope. Axis countries also expand arms sales to the Global South, continuing recent trends. Between 2020 and 2024, for example, the main suppliers of arms to Africa were Russia (which accounted for 21 percent of total African imports of major arms) and China (18 percent).24

Axis countries might broaden the scope, frequency, and geographic location of exercises and training missions to improve joint warfighting, intelligence sharing, command and control arrangements, and interoperability. Between January 2019 and July 2025, China and Russia conducted nearly a dozen combined strategic aerial patrols, including with Russian Tu-95 and Chinese H-6N and H-6K bombers capable of carrying nuclear weapons.25 These patrols could increase in number and geographic scope, including in the western Pacific and off the U.S. coast. While many of these exercises and training missions could be bilateral, there might also be an increase in multilateral exercises and training missions. In March 2025, for example, Iran, Russia, and China conducted a joint naval exercise—called Marine Security Belt 2025—in the Gulf of Oman, marking the fifth year of joint drills.26 Several other countries, including Azerbaijan, Iraq, Kazakhstan, Oman, Pakistan, Qatar, Sri Lanka, South Africa, and the United Arab Emirates, observed the exercise.

In addition, axis countries could deepen bilateral defense industrial base cooperation. A modern-day defense industrial base involves the production of defense and dual-use items by commercial companies and state-owned enterprises across multiple domains. Key domains include maritime, air, ground, space, cyber, and nuclear. Axis countries could increase cooperation in areas such as unmanned and autonomous platforms, integrated air and missile defense, space and counterspace, submarines, missiles, and emerging technologies such as AI and quantum.27 Cooperation could take several forms: the codevelopment, coproduction, and co-sustainment of weapons systems or components involving industrial firms from two or more axis countries, joint ventures, or transnational mergers and acquisitions.

Next, axis countries could increase their commitment to defend each other in case of external attack through a deeper bilateral treaty or other agreement that commits signers to collective assistance. The most important relationship is likely between China and Russia, which agreed to a “no limits” friendship in February 2022 and reaffirmed it in February 2025.28 Chinese-Russian relations could deepen if their leadership committed to collective assistance in the case of an armed attack. In addition, bilateral relations have strengthened between other axis countries, except Iran and North Korea, which do not have a formal alliance. In March 2021, for example, China and Iran agreed to a 25-year strategic partnership, which included Chinese investment in Iran and imports of discounted Iranian oil to China.29 In June 2024, Russia and North Korea signed the Treaty on Comprehensive Strategic Partnership, which commits the countries to mutual military and other assistance if the other is invaded.30 In January 2025, Russia and Iran signed a 20-year pact that formalized close ties between the two countries.31 However, the pact did not constitute a military alliance and required no direct obligations from either party. Overall, a future development that deepens bilateral relations would likely involve building and expanding these commitments.

Finally, a deepening coalition could include increased combat assistance—including the deployment of soldiers—to other axis members engaged in wars. There have already been several examples. China, Iran, and North Korea have provided military assistance to Russia for its war against Ukraine. In late 2024, North Korea sent approximately 12,000 combat forces to Russia’s Kursk Oblast, where Ukraine seized Russian territory. In early 2025, North Korea deployed roughly 3,000 additional soldiers for combat against Ukrainian forces.32 Future examples could include growing Chinese and Russian security and intelligence assistance to Iran and its partner forces in the Middle East, Russian and Chinese aid to North Korea in a conflict on the Korean Peninsula, or Russian and North Korean assistance to China in a conflict in the Taiwan Strait, South China Sea, or East China Sea.

Several factors could lead to deepening bilateral relations. First is an increased threat, such as an arms race with the United States, European countries, or Asian countries such as Australia, Japan, and South Korea. Significant increases in defense spending and potential offensive capabilities—such as fifth- and sixth-generation aircraft, nuclear weapons, bombers, submarines, and ballistic, cruise, and hypersonic missiles by the United States, Europe, and Asian countries—could increase the threat perception in Beijing, Moscow, Tehran, and Pyongyang. An escalating conflict in the Middle East, a protracted war in Ukraine, or an escalating crisis in the South China Sea, East China Sea, or Taiwan Strait could also increase the perception of threat among axis countries. A second factor is growing common interests, including those against the West. As Stephen Hadley, President George W. Bush’s national security adviser, wrote, “There is a shared anti-Westernism, opposition to democracy, and embrace of authoritarian alternatives. What truly binds the axis is not ideology but a common opposition to U.S. power and the international system it sustains.”33 Third is the persistence or deepening of strong ties between axis leaders. Most significant would be a deepening of ties between Xi and Putin, whose relationship could serve as the lynchpin of axis relations.

Multilateral Alliance

A final scenario is a multilateral alliance. In this case, axis countries begin to establish multilateral arrangements and include high levels of cooperation, such as an agreement that commits signers to collective assistance in case of external attack.34 A multilateral alliance would likely involve strengthened relations in several areas, such as multilateral joint exercises and training and integrated defense industrial cooperation across three or more countries. There would be several differences from previous scenarios.

Axis countries could establish a multilateral arrangement—such as a treaty, defense pact, nonaggression pact, entente, or other agreement—committing signers to collective assistance in case of external attack or other types of arrangements. The agreement could be overt or covert. Historical examples include the Treaty of the Holy Alliance of 1815 between Austria, Prussia, and Russia; the Atlantic Charter of 1941, which established NATO; and the Warsaw Pact during the Cold War, which included the Soviet Union and Soviet satellite countries in Eastern Europe.35 Axis countries could also establish a multilateral military structure that includes a military committee, joint war plans, and other committees to cooperate at the strategic, operational, and tactical levels. The Warsaw Pact had a unified command under Soviet leadership. The command structure included a Combined Armed Forces Command, located in Moscow, which comprised military officers from all the Warsaw Pact countries.36

Several factors could lead to a multilateral alliance. The first is a major increase in the nature or scope of the threat, such as the outbreak of war between an axis member and the United States, Japan, Taiwan, South Korea, or one or more European countries. Another cause could be nuclear proliferation to South Korea, Japan, Poland, or another country, which could increase the perception of threat in one or more axis members. A second factor is growing ideological solidarity or other common interests between axis countries. Third is domestic politics. Regime change in one or more axis countries could bring to power a leader who is willing to expand axis cooperation for their own interests. Strong, ambitious, and expansionist leaders in Beijing or Moscow could push for greater multilateral collaboration to aggregate power among axis countries.

Conclusion

The most likely future security arrangement is deepening bilateral relations. Under this arrangement, axis countries might increase military and dual-use exports and imports, expand the scale and scope of bilateral and potentially multilateral exercises and training, integrate defense industrial cooperation, deepen bilateral treaties or pacts that commit the signatories to greater military cooperation and even mutual defense in case of attack, and deploy soldiers to fight in the wars of other axis countries. This scenario is likely for several reasons.

First, the degree of common threat is likely to increase. European and Asian countries—such as France, Germany, Japan, and South Korea—are likely to raise defense spending and strengthen their defense industrial bases. Defense spending is rising among these countries and across the globe more broadly, with global defense spending increasing from $2.23 trillion in 2023 to $2.46 trillion in 2024.37 Defense budgets across the European Union are likely to rise by as much as $84 billion by 2027, equivalent to approximately 0.5 percent of GDP.38 In June 2025, NATO Secretary General Mark Rutte called for a 400 percent increase in Europe’s air and missile defense budget.39 Defense budgets in Asia are also rising. As one analysis concluded, “strategic drivers—such as China’s military modernization and increasing assertiveness, and North Korea’s advancing nuclear weapons program—galvanize threat perceptions in the region.”40

Consequently, an arms race is more likely than a détente. In addition, war involving Russia is likely to continue in Eastern Europe, and conflict is likely to persist between Israel and Iran (including Iranian partners) in the Middle East, with China and Russia providing some assistance to Iran and its partners. Further, there is a significant risk of conflict in the Taiwan Strait, South China Sea, and Korean Peninsula. Consequently, security competition between axis countries and democratic countries in Europe, Asia, and the Middle East is likely to remain significant and could increase in intensity.

Second, there is likely to be a deepening of common interests between axis countries, which aim to undermine democracy and increase their power and influence in multilateral institutions such as the United Nations and other international and regional institutions.41 A particular focus may be balancing against what they view as U.S. imperialism or hegemony.

Third, domestic factors will likely increase security cooperation among axis countries. Whereas Khamenei’s health has been the subject of speculation, Xi and Putin—the lynchpins of the axis—are unlikely to step down in the next three to five years, and their relationship has strengthened, not weakened.42 There is also little evidence that Putin will curb his revanchist interests in Ukraine or other areas, such as Eastern Europe, Central Asia, the Middle East, and Africa; that Iran will walk away from its partners and proxies in the Middle East; or that Xi will curb his expansionist ambitions in Asia and other areas.

Growing collaboration between axis countries would have significant implications for the future of warfare. For example, cooperation could increase the possibility of multi-theater war. Would Russia take advantage of a U.S.-China war in the Taiwan Strait or South China Sea to move into the Baltics or other regions? Would China or Russia take advantage of a war in the Korean Peninsula that pulls in North Korea, South Korea, the United States, and other countries? Between World War II and 2012, the United States sized its military to fight two wars at the same time.43 But that changed with the Defense Strategic Guidance, which altered the two-war standard to “secur[ing] territory and populations and facilitat[ing] a transition to stable governance” in one region, while “denying the objectives of––or imposing unacceptable costs on––an opportunistic aggressor in a second region.”44 However, this force construct is likely inadequate for tomorrow’s challenges that could require fighting two wars simultaneously.

Looking forward, there are several indications and warnings that could provide clues to the future evolution of the axis and the implications for the future of warfare:

  • Arms Exports and Imports: Is there an increase or decrease in exports and imports of military and dual-use items between axis countries? Are axis countries shipping more or fewer military and dual-use items by ship, rail, truck, or air? Is the scope of trade expanding or shrinking, including in sensitive areas such as nuclear weapons, space, stealth, hypersonics, quantum, and emerging technology?
  • Joint Exercises and Training: Are exercises and training efforts primarily bilateral or multilateral? Do exercises and training efforts prepare for large-scale combat against the United States and European and Asian countries, including across land, air, maritime, space, and cyber domains? Do they include closer command and control arrangements and sensitive intelligence sharing?
  • Defense Industrial Base: Is there an increase or decrease in bilateral or multilateral defense industrial cooperation between axis companies and state-owned enterprises, including codevelopment, coproduction, co-sustainment, joint ventures, and mergers and acquisitions? If there is greater cooperation, in what areas is it occurring? And what is the scope of cooperation?
  • Treaties and Defense Pacts: Do axis countries create or deepen bilateral or multilateral treaties or other agreements that commit signers to collective assistance in case of external attack? Or is there a weakening of commitments? Are agreements formal or informal? Are they overt or covert? Are there indications of warming or cooling relationships between the leaders of axis countries?
  • Military Aid During War: Do countries provide military assistance—such as weapons, troops, and intelligence—to other axis countries during wars? Or do they refrain from providing aid, especially for short wars? What types of aid are they willing to provide? Are axis countries willing to shed blood for each other, including through combat deployments?
  • Military Structure: Do axis countries establish a military organizational structure, develop joint war plans, or create other types of cooperative arrangements at the strategic, operational, or tactical levels? Or is there insufficient trust or interest to establish a multilateral military structure?

In addition, there are several indications and warnings that might cause axis relations to strengthen or weaken:

  • Arms Buildup: Is there an arms race, including a significant increase in defense spending, between axis countries and their competitors in Europe, Asia, and the United States? Are countries building offensive military capabilities?
  • Nuclear Proliferation: Is there a proliferation of nuclear weapons, including in such countries as South Korea, Japan, and even Iran? Or do potential nuclear states refrain from building nuclear weapons?
  • War: Does war persist in Europe and the Middle East? Is there a new outbreak of war involving an axis country? Is there an end to a major war, such as a ceasefire or peace agreement in Ukraine? Is there a major decrease in the intensity of conflict, such as between Israel and Iran (including Iranian partners and proxies)?
  • Regime Change: Is there a change in leadership in one or more axis countries? Is a new leader more or less inclined to strengthen axis relations or to expand territory? Or is there continuity of leadership in core axis countries, especially China and Russia?
  • Domestic Instability: Is there significant domestic economic, social, or political instability in one or more axis countries that could impact axis relations? Or is there relative stability within axis countries?
  • Future of Security Institutions: Does NATO grow stronger or weaker over the next three to five years? Is there a deepening of security ties—including a multilateral security institution—between the United States and countries in Asia such as Australia, Japan, and South Korea?
  • Divisions and Fissures: Are there increases or decreases in policy fissures between axis countries? How serious are the differences and in what areas?

Answers to these questions will provide useful and timely indicators of the strength or weakness of axis relations. They will also have significant implications for the future of warfare, including the possibility of multi-theater wars involving more than one axis country. Growing cooperation increases the possibility that a war with one axis country could expand to multiple fronts, causing simultaneous demands for such countries as the United States.

Please consult the PDF for references.

Seth G. Jones is president of the Defense and Security Department at the Center for Strategic and International Studies (CSIS) in Washington, D.C.

Commentary is produced by the Center for Strategic and International Studies (CSIS), a private, tax-exempt institution focusing on international public policy issues. Its research is nonpartisan and nonproprietary. CSIS does not take specific policy positions. Accordingly, all views, positions, and conclusions expressed in this publication should be understood to be solely those of the author(s).

© 2025 by the Center for Strategic and International Studies. All rights reserved.

Tags

Russia, Europe, Middle East, China, Iran, Defense and Security, Ukraine War, Geopolitics and International Security, and Defense Industrial Base