Welcome to the special edition of China Scholar Insights! I am SUN Chenghao, a fellow with the Center for International Security and Strategy (CISS) at Tsinghua University. ChinAffairsplus is a newsletter that shares Chinese academic articles focused on topics such as China’s foreign policy, China-U.S. relations, China-European relations, and more.
I have followed the relationship through very different moments—from debates over NATO and European strategic autonomy to the war in Ukraine and, more recently, renewed tensions between Washington and its European allies.
One question has stayed with me throughout: what really holds the transatlantic alliance together—and what happens when some of those foundations begin to change?
That is the question I explore in this article, published in Qiushi（《求是》）. Rather than viewing current U.S.-European tensions simply as the result of particular leaders or policy disputes, I look at the deeper forces reshaping the alliance: changes in its economic foundations, political ideas, perceptions of international responsibility, and the balance between security dependence and strategic autonomy.
My conclusion is not that the transatlantic alliance is heading toward collapse. Its security interests, institutional ties, and economic connections remain remarkably resilient. But the logic of the relationship is changing. The United States is moving from “leading the West” toward “managing the alliance,” while Europe is seeking greater strategic autonomy without breaking away from Washington.
What we may be witnessing, therefore, is not the end of the transatlantic alliance, but its transformation into a more transactional and less cohesive relationship—with consequences that extend well beyond Europe and the United States.
For ChinAffairsplus readers, I’m sharing an English translation of the article below. The original Chinese article was published in Qiushi, No. 15, 2026. The English version was translated by Chen Weihan and should not be regarded as an official translation by Qiushi.
Questions, comments, or criticisms are welcome at sch0625@gmail.com
In recent years, the transatlantic alliance has come under severe strain. While doubling down on “America First,” the current US administration has demanded that Europe take more responsibility for security and has continued to pressure Europe in trade, technology, and other fields. Europe, for its part, has sought to preserve cooperation within the alliance while accelerating its pursuit of strategic autonomy and the development of its defense capabilities. Differences between the two sides over defense burden-sharing, economic and trade rules, technology governance, and the international order have grown increasingly pronounced. A thorough analysis of the historical logic behind the evolution of the transatlantic alliance, the deep-rooted causes of its current rifts, its future prospects, and its impact on the international landscape is of practical significance for accurately understanding changes unseen in a century and the trend toward a multipolar world.
The transatlantic alliance is not merely an alliance of convenience based on converging interests. It is an enduring relationship underpinned by three mutually reinforcing foundations, namely, the security structure, institutional support, and ideational affinity. Since the end of World War II, the alliance has weathered repeated tests, including Cold War confrontation, the collapse of the Soviet Union and the ensuing restructuring of the international order, the shock of the war on terror, and great-power rivalry.
In response to the needs of the Cold War, the United States, the United Kingdom, France, and nine other countries signed the North Atlantic Treaty in 1949 and established the North Atlantic Treaty Organization (NATO) on the core principle of “collective defense”. The treaty stipulates that an armed attack against any one member is to be regarded as an attack against the alliance as a whole. NATO’s creation marked the emergence of a highly integrated US-European security relationship.
During this period, the alliance operated according to the core logic of a “security community”, whose essence lay in jointly responding to external threats. The United States maintained large-scale troop deployments in Europe over the long term and assumed the role of NATO’s leader, while most European countries depended heavily on the US nuclear umbrella and its advanced military and intelligence capabilities. Although the United States and Europe differed on specific issues such as strategic autonomy, nuclear policy, and military deployments, those differences were consistently overshadowed by more pressing security needs. The experience of this period showed that as long as an external threat was sufficiently grave, internal tensions within the US-European alliance would remain secondary.
After the Cold War, the external threats facing the United States and Europe declined sharply. According to the assumptions of traditional alliance theory, the transatlantic alliance should therefore have loosened or even dissolved. Yet the opposite occurred: NATO not only survived, but also expanded and transformed its functions. It had only 16 members at the end of the Cold War; by July 2026, that number had doubled to 32. NATO’s functions also gradually expanded beyond traditional collective defense to encompass regional interventions, counterterrorism cooperation, cybersecurity, and other fields.
The key to this development was the institutionalization of the alliance. Through rules, procedures, and organizational structures, the NATO-centered transatlantic system institutionalized security cooperation between the United States and Europe, shifting the alliance from being “threat-driven” to “institution-driven.” Stable mechanisms not only provided a platform for deliberation and decision-making, but also offered a gateway to dependence through bureaucratic cooperation, coordination between political and military authorities, military interoperability, and long-term collaboration, thereby raising the cost of “going their separate ways.” Even though the United States has become less willing in recent years to invest in European security and Europe has repeatedly stressed strategic autonomy, NATO’s institutional continuity has kept both sides anchored within the alliance framework. As the Russia-Ukraine conflict has dragged on, the United States and Europe have differed over defense burden-sharing. Yet European countries, compelled by their security needs, have still increased defense spending substantially and established additional mechanisms for defense cooperation. This further demonstrates that the institutional mechanisms themselves have become an important foundation sustaining the transatlantic alliance.
The transatlantic alliance is not merely a form of security cooperation; it also embodies political and ideological alignment based on such values as “freedom and democracy.” Unlike security structures and institutional mechanisms, this ideational affinity has not operated only during a particular historical period. It has served as a cultural bond and an intellectual and normative foundation throughout the alliance’s development.
During the Cold War, the United States and Europe gradually developed a shared political and ideological outlook centered on liberal democratic systems, market economies, and a “rules-based international order.” From the 1990s into the early 21st century, both sides generally believed that their institutional model was attractive. Their strategic focus gradually shifted from preserving the existing security order to shaping and expanding an international order dominated by them. Whether through NATO’s eastward expansion, the European Union’s eastward enlargement, or external actions carried out in the name of “democracy promotion,” these initiatives bore a distinct imprint of exporting values. Even after major disagreements over issues such as the Iraq War, the United States and Europe retained a high degree of alignment in their basic understanding of the “liberal international order.” They continued to share a common discourse and value base on global governance, the reform of international organizations, and the formulation of international rules. This enabled the transatlantic alliance to evolve from a traditional military alliance into a strategic relationship with pronounced political attributes and a clear bloc character.
In recent years, economic and trade frictions, disputes over defense burden-sharing, and differences in strategic perceptions within the transatlantic alliance have appeared on the surface to be conflicts over specific policies. In fact, they reflect profound changes in the economic foundations, political ideas, and consensus on values underpinning long-term cooperation between the two sides.
On the economic front, economic globalization has not only changed the West’s relationship with the rest of the world; it has also weakened the US-European consensus on economic development. Free trade, multiculturalism, and the Western-led international institution that emerged after the Cold War once constituted important pillars of the so-called “liberal international order” promoted jointly by the United States and Europe. Both sides broadly believed that open markets, capital flows, cross-border movement of people, and the spread of institutions could not only improve economic efficiency but also move the global order in a direction conducive to their long-term dominance.
Yet as economic globalization deepened, problems such as industrial relocation, the loss of manufacturing jobs, widening income gaps, and uneven regional development continued to accumulate, gradually turning some groups into the “losers” of globalization. Particularly after the 2008 international financial crisis, confidence in free markets and economic globalization declined markedly across Western societies, and a growing number of people began to question whether an open economic system could continue to deliver broadly shared prosperity. The United States and Europe have increasingly diverged over how to respond to the impact of economic globalization.
The United States moved relatively early toward a new economic strategy centered on industrial policy, trade protection, and supply chain security. It has placed growing emphasis on harnessing the power of the sovereign state to strengthen state capacity and reshape strategic planning and resource allocation, with the aim of revitalizing the domestic economy and enhancing strategic competitiveness. “America First,” the reshoring of manufacturing, stronger industrial subsidies, and more robust economic security policies all reflect an adjustment—and even a correction—to the neoliberal model of economic globalization. Europe likewise faces declining industrial competitiveness and sluggish economic growth. Constrained, however, by its supranational governance model and mechanisms for coordination among member states, it still seeks, on the whole, to pursue reform within the framework of open markets, free trade, and the multilateral economic system. It is more inclined to advance policy adjustments through rules and collective consultation. Differences between the United States and Europe have thus continued to grow in trade, industrial policy, economic security, supply chain restructuring, and other fields.
On the political front, issues as identity and “boundaries” have moved to the center of debate. During the Cold War, the Soviet threat largely obscured differences between the United States and Europe over immigration, identity, and social governance. Following the end of the Cold War, as the common external threat receded and economic globalization deepened, questions over who belongs to the “West” and how the boundaries of the community should be defined gradually became major issues in political debate on both sides of the Atlantic.
The United States has increasingly emphasized the primacy of national borders, sovereignty, and citizenship, and has tended to ground the political community in the nation-state. Europe, by contrast, has long pursued supranational integration, seeking to construct a broader European identity beyond national identities. In recent years, the migration crisis, refugee issues, and difficulties with social integration have further magnified this divergence. As a result, differences between the United States and Europe are no longer confined to specific immigration policies; they have become a contest over identity centered on “who counts as a Westerner” and “where the boundaries of the West lie.”
The United States and Europe are also diverging over international responsibilities. After the Cold War, they generally regarded themselves as shapers of the global order and promoters of international rules, and viewed multilateralism, free trade, human rights narratives, and the export of institutions as important manifestations of their strengths.
In recent years, their understandings of what international responsibilities they should shoulder and how the international order should be shaped have gradually diverged. The current US administration no longer treats maintaining the Western and global order as a “responsibility.” Instead, it stresses “America First” and demands that Europe prove its value to the alliance by bearing higher costs. Europe, meanwhile, remains inclined to regard multilateralism, the promotion and diffusion of norms, and global governance as important components of its international identity, and it is wary of the United States’ increasingly evident unilateralism. Debate in Europe over “US reliability,” “strategic autonomy,” and “European responsibility” has continued to intensify, reflecting concern about the changing US role and renewed consideration of Europe’s own position. These different perceptions of international responsibility have widened policy differences between the two sides on security, trade and economic relations, technology, climate change, global governance, and other issues.
The current changes in the transatlantic alliance do not mean that the common interests and foundations for cooperation between the two have disappeared altogether. Rather, the principal logic sustaining the alliance is being recalibrated. Although the two sides are finding it harder to maintain the high degree of strategic consensus that prevailed after the Cold War, they still share common needs with regard to security interests, institutional ties, and global interests. Whether responding to regional security risks, maintaining transatlantic economic ties, or coordinating on global issues, the two sides still need each other, and neither can bear the consequence of a complete rupture in the alliance. For this reason, the transatlantic alliance will not disintegrate simply because differences are multiplying. It is more likely to enter a new phase of adjustment in which common interests persist even as shared understandings gradually weaken.
Over the longer term, security cooperation, economic and trade ties, and institutional coordination within the transatlantic alliance will continue to play an important role. Its internal cohesion, however, will increasingly be shaped by practical needs and strategic calculations.
From the US perspective, its approach to the transatlantic alliance is shifting from “leading the West” to “managing the alliance.” This is because the strategic priorities of the United States, both at home and abroad, are changing. Compared with its longstanding post-Cold War role as the “guardian” of the Western liberal international order, the United States now places greater emphasis on giving priority to domestic economic competitiveness, industrial development, social governance, and other issues. It is also inclined to direct its limited resources toward areas of greater strategic priority, such as the Indo-Pacific region. The importance of the transatlantic alliance has therefore not declined in substantive terms, but its functions are being recalibrated. In the future, it will increasingly serve US needs to preserve its competitive edge internationally and shape a favorable strategic environment. Against this backdrop, the United States will not readily abandon Europe as an important ally, and its support for Europe will continue, but it will highlight “costs and benefits.”
From the European perspective, the transatlantic alliance is undergoing an adjustment from dependence on the United States toward greater strategic autonomy. In recent years, Europe has strived to advance defense cooperation, defense-industrial integration, economic security, and the development of capabilities in key technologies. Strategic autonomy is gradually being translated from a political proposition into concrete policy. Yet European countries differ in levels of development, security perceptions, and strategic cultures, while the nuclear deterrence, intelligence systems, and strategic power-projection capabilities provided by the United States will remain resilient in the near term. The practical goal of European strategic autonomy is therefore not to break away from the United States, but to enhance Europe’s capacity for action, capacity to withstand risks, and policy autonomy within the alliance. Europe is also increasingly aware that genuine strategic autonomy is reflected not only in the development of military capabilities, but also in industrial competitiveness, scientific and technological innovation, and the capacity to shape global rules. How to strengthen its own strategic agency while maintaining cooperation with the United States will be a major challenge for Europe as it manages the transatlantic alliance in the years ahead.
The changing transatlantic alliance will also have far-reaching implications for the international system and global governance. At the level of the international system, adjustments within the alliance mean that the relative capacity of the United States and Europe to dominate the international agenda and shape international rules will be compromised. International politics will increasingly be characterized by interaction and coordination among different forces rather than by arrangements under the dominance of a single power. The autonomy of Global South countries and emerging powers in international affairs will grow constantly, as will their voice in reforming the global governance system and in international financial governance, global climate governance, digital governance, and other fields. At the level of global governance, diverging perceptions and interests within the transatlantic alliance may weaken the ability of the countries concerned to coordinate on certain international issues, making global governance more consultative, pluralistic, and decentralized. The formation of international rules will increasingly depend on coordination and cooperation among different countries and regions, rather than being driven primarily by a small number of Western countries.
The profound adjustment of the transatlantic alliance also shows that the old security logic built on exclusive alliances, bloc divisions, and bloc politics is increasingly ill-suited to the prevailing trends of world multipolarity, economic globalization, and greater democracy in international relations. As the international balance of power undergoes profound change with the collectively rise of developing countries, a growing number of countries hope to participate in international affairs on an equal footing and jointly shape international rules, rather than passively accept institutional arrangements dominated by a small number of Western countries. It is against this backdrop that the countries of the Global South, represented by China, are upholding the banner of building a human community with a shared future, acting in line with the trend toward greater democracy in international relations, insisting on true multilateralism, and advocating an equal and orderly multipolar world and universally beneficial and inclusive economic globalization. These efforts will undoubtedly help move the international order in a fairer and more equitable direction.
Translated by Chen Weihan, Beijing Foreign Studies University
About the Author
SUN Chenghao 孙成昊: Dr. SUN Chenghao is a senior fellow and head of the U.S.-Europe program at the Center for International Security and Strategy (CISS), Tsinghua University; Munich Young Leader with Munich Security Conference. He was a visiting scholar at Yale Law School in 2024. His research interests include U.S. domestic and foreign policy, China-U.S. relations, transatlantic relations, AI and International security, etc. He teaches a graduate-level course on Transatlantic Relations in Tsinghua University. Dr. Sun has co-authored dozens of reports and books. He is the Top 1% Highly Cited Scholar (2024 & 2025) in China according to statistics of China National Knowledge Infrastructure (CNKI). Dr. Sun is also Council Member of the Chinese Association of American Studies.
