Alliance Networking in Europe and the Indo-Pacific

Will Donald Trump’s return to the White House lead to an unraveling of the security ties that the United States has cultivated in and between Europe and the Indo-Pacific? U.S. allies in Europe and the Indo-Pacific have cultivated closer security ties with each other in recent years, as illustrated by NATO’s efforts to expand cooperation with its four Indo-Pacific partners (Australia, Japan, South Korea, and New Zealand), growing bilateral ties between individual European and Indo-Pacific allies, and various high-profile defense-industrial projects such as the AUKUS submarine deal or the development of a next-generation fighter jet between the United Kingdom, Japan, and Italy. Interestingly, such growing cross-regional security cooperation among U.S. allies in distant regions is gaining ground at a time when the U.S.-led regional alliance systems in Europe and the Indo-Pacific are themselves exhibiting important changes, and evolving towards more nodal or flexible patterns of bilateral and “minilateral” defense cooperation. The 2023 Camp David agreements between the United States, Japan, and South Korea are a case in point.

These ongoing transformations challenge two longstanding assumptions about U.S.-led alliances. The first has to do with the United States organizing its alliances around regionally defined threats and priorities, and with the notion that U.S-led regional alliance systems barely interact with each other. The second relates to the contrasting approach to structuring alliances in Europe and Asia. The first is the quintessential example of a multilateral alliance structure, while the latter is typically characterized as a “hub-and-spokes” model, in that the United States enjoys a series of bilateral alliances with countries that have limited defense linkages with each other and are connected only indirectly, through the U.S. “hub.”

As President Joe Biden leaves office, Donald Trump returns to the White House, and key allies in Japan, South Korea, Germany, and France turn their attention inwards, the future of cooperation within and between U.S. alliance systems in Europe and the Indo-Pacific is in question. Yet, more structural drivers like China’s strategic rise, Russian revisionism or growing cooperation between Russia, China, and North Korea are also at play and may point towards continuity.

Archetypal Types of Alliance Structures

Both the notion that defense cooperation was organized around regions and that the European and Asian alliance architectures exhibited radically different features are part real and part myth.

For one thing, we saw important instances of cross-theater cooperation and engagement during the Cold War, as illustrated by the involvement of multiple European allies in the Korea War; Britain’s Five Power Defence Arrangements with Australia, Malaysia, New Zealand, and Singapore; French engagement in Vietnam; or Japan’s (unsuccessful) bid to establish informal ties to NATO in the early 1980s. Despite these instances, however, the bulk of security cooperation remained regional.

For another, multilateralism and hub-and-spokes are ideal-type concepts. Even in Cold War Asia, there were instances of spoke-to-spoke and minilateral cooperation, notably involving Japan and South Korea. Similarly, within Cold War NATO, meaningful divisions of labor existed alongside sub-regional clusters or minilaterals. One example is the cooperation between Norway, Denmark, and the United Kingdom to track Soviet submarines in the so-called Greenland-Iceland-United Kingdom gap. Still, even if alliance structures were never purely bilateral or multilateral, the basic distinction between Europe’s multilateral and Asia’s bilateral alliance architectures remained largely intact throughout the Cold War period.

Co-Evolution

Over the past three decades, the region-centric and mirror-image assumptions have become increasingly blurred. In Europe, the collapse of the Soviet Union led different allies to turn their attention to more localized challenges and cluster around bilateral and minilateral nodes of cooperation focusing on different threats and tasks. Eastern and northeastern European states tailored and coordinated their defense efforts around Russia’s residual threat, which became more prominent after the Russo-Georgian war in 2008. Western and southern European states largely configured their defense policies around such challenges as regional instability and terrorism. Although NATO always provided some unifying coherence, throughout much of the 2000s and the early 2010s, the center of gravity of European defense cooperation shifted to bilateral and minilateral nodes focusing on sub-regional or local threats, as illustrated by the launch of Nordic Defense Cooperation, the Franco-British Lancaster House Agreements, or the development of the British-led Joint Expeditionary Force.

To be sure, Russia’s annexation of Crimea in 2014 revitalized NATO and multilateral cooperation in Europe, particularly following the alliance’s decision at its 2016 summit in Warsaw to deploy four multinational battalions to the eastern front. That said, NATO allies still held divergent threat perceptions, and it was mainly central and eastern European countries that led efforts to strengthen deterrence, both in a NATO context and through bilateral and sub-regional cooperation. Wary of such intra-European divergences, allies along the northern and eastern flanks have been particularly eager to strengthen bilateral ties with the United States — a tendency that was embraced by the first Trump administration. While Russia’s full-blown invasion of Ukraine in 2022 spurred greater multilateral defense cooperation within NATO, bilateral and sub-regional defense cooperation has broadly persisted across different U.S. administrations.

In the Indo-Pacific, an opposite trend has emerged. China’s increasingly assertive behavior has catalyzed greater strategic cooperation among previously disconnected U.S. allies and partners. Japan has emerged as a key regional node, having strengthened bilateral ties with countries like Australia and the Philippines, and becoming involved in various trilaterals (notably with South Korea and the United States) and quadrilaterals. Meanwhile, New Zealand and the Philippines recently signed a mutual logistics support agreement, and worked to expand defense cooperation more broadly. Other examples of spoke-to-spoke interaction include the Philippines-Australia Status of Visiting Forces Agreement or the South Korea-Australia Comprehensive Strategic Partnership. While the Biden administration’s “latticework” approach stimulated greater spoke-to-spoke ties, these same efforts can be traced back to the 2018 U.S. National Defense Strategy as the Trump administration’s focus on China paved the way for a more networked security architecture in Asia.

Cross-Regional Interconnectivity

Alongside the ongoing transformation of respective alliance systems in Europe and Asia challenging the notion of mirror-image alliance architectures, the two regions are becoming increasingly interconnected, resulting in enhanced cooperation between otherwise traditionally separate alliance ecosystems. The context here is the gradual but certain cross-theater threat convergence among U.S.-led alliances, spurred by three distinct but closely interrelated concerns related to China’s rise. First, U.S. allies in the Indo-Pacific and — increasingly — Europe view China as posing a sustained and multidimensional challenge to international order. Second, growing political, economic, military, and technological cooperation between Beijing, Moscow, and Pyongyang is linking the European and Indo-Pacific theatres in tangible ways. Third, China poses a significant challenge to Indo-Pacific security, and to U.S. military power more generally. Although the latter trend affects Indo-Pacific allies more directly, it also has a significant impact for Europeans given the global importance of the Indo-Pacific in terms of trade, security and technological innovation, and, critically, the potential impact of an Indo-Pacific contingency on U.S. global force allocation.

These shared concerns over China’s rise have spurred the recognition in both alliance systems that more cross-regional cooperation is necessary. Russia’s full-scale invasion of Ukraine in February 2022 has been a key accelerator in this regard. Surely, European wariness about the strategic challenges associated with China’s rise predate the Ukraine war, as indeed demonstrated by NATO’s references to China in its 2019 London Declaration or, even more clearly, in the alliance’s 2021 Brussels Summit Communiqué, which devoted two full paragraphs to China. Yet it has been Beijing’s “decisive enabling” of Moscow’s war effort in Ukraine and fast-expanding military cooperation between Moscow and Pyongyang — most recently illustrated by 10,000 North Korean troops joining Russia in combat — that is tying the two alliance systems ever more closely together.

In Asia, U.S. allies worry that Russian technology transfers and military cooperation with North Korea and China might complicate their respective threat environments. In this regard, South Korea has even considered supplying weapons to Ukraine in addition to the more indirect military support that other Indo-Pacific countries have already provided. Additionally, the Biden administration’s emphasis on connecting like-minded allies to push back against the global challenge posed by an authoritarian axis has been an important factor behind growing cross-regional cooperation.

Thus, while U.S. allies in NATO and the Indo-Pacific may differ when it comes to their main threat referents and areas of responsibility, their strategic and operational priorities appear to increasingly align. Each respective alliance system grapples with the question of how to strengthen deterrence in the face of great-power revisionism and related anti-access and area-denial challenges, and how to generate the forces, operational concepts, capabilities, and technologies required to that end. Additionally, NATO countries’ concern about U.S. resource diversion towards the Indo-Pacific necessitates an improved understanding as to how an Indo-Pacific contingency may affect U.S. military resources and planning. To this end, the two regional alliance systems increasingly benefit from mutual learning in operational planning or the development of joint capabilities and technologies.

Indeed, cooperation between U.S. allies in Europe and the Indo-Pacific has picked up considerably in recent years. An important milestone in this regard was NATO’s new Strategic Concept, approved during the alliance’s 2022 summit in Madrid, which underlined how “developments in the Indo-Pacific can directly affect Euro-Atlantic security” and called for strengthening dialogue and cooperation. Against this backdrop, NATO has recently concluded individual partnership agreements with Japan, Australia, South Korea, and New Zealand and launched joint projects on Ukraine, artificial intelligence, disinformation, and cyber security.

At the bilateral level, countries like France, the United Kingdom, and, to a lesser extent, Germany have developed and diversified their security and defense partnerships across the Indo-Pacific with focus areas such as logistics support, maritime security, information exchanges, space cooperation, military exercises, and arms sales. For its part, Warsaw has turned to Seoul for the delivery of tanks, howitzers, and rocket launchers as a result of South Korea’s defense-industrial capacity and greater openness to technology sharing and co-production. In a similar vein, South Korea and Romania concluded a defense cooperation agreement in the spring of 2024 and announced Romania’s acquisition of K-9 howitzers, with more sales to follow.

U.S. allies in Europe and the Indo-Pacific have also intensified their cooperation through various cross-regional minilateral initiatives, either with or without U.S. involvement. The AUKUS trilateral security partnership between the United States, Britain, and Australia arguably stands out. AUKUS includes the provision of nuclear submarines to Australia and cooperation in emerging technologies, accompanied by a force posture agreement that will see U.S. and British submarines begin rotational deployments to Australia’s HMAS Stirling naval base in 2027. Another prominent cross-theater defense-industrial partnership tying the two regions together is the U.K.-Japanese-Italian sixth-generation fighter jet program.

In short, we are witnessing growing synergies between the two regions, crystalizing through variable formats and nodes of cooperation (primarily bilateral and minilateral) involving the United States and its European and Indo-Pacific allies and partners. Growing cooperation between Russia, China, and North Korea on the back of the Ukraine war has surely raised awareness amongst NATO and America’s Indo-Pacific allies about the two regions’ strategic interconnectedness, spurring greater cross-regional cooperation — and so has the Biden administration’s emphasis on countering the Sino-Russian threat to global order. Nevertheless, the seeds for greater cross-theater cooperation were already planted during the first Trump administration, which went to great lengths to get Europeans to take China seriously, thus paving the way for greater cooperation between NATO and Indo-Pacific partners.

Into a Convergent Future?

Growing cross-regional cooperation between European and Indo-Pacific allies has coincided with a transformation of defense cooperation patterns within regions, with Europe seeing more initiatives below the NATO level and the Indo-Pacific witnessing greater spoke-to-spoke cooperation. Against the backdrop of these twin developments, the myths about U.S.-led alliances being framed exclusively in regional terms and following a multilateral versus bilateral logic appear to be eroding.

The convergence between traditionally separate alliance systems has been driven by widespread awareness about the return of great-power competition, the strengthening of political-military cooperation between revisionist powers China and Russia, and shared concerns about maintaining credible deterrence as the United States faces two great-power adversaries simultaneously. In this regard, the Russo-Ukrainian war has underscored both the necessity of and the challenges associated with increased cooperation within and between Europe and the Indo-Pacific.

Given the centrality of the United States in the networking of Euro-Atlantic and Indo-Pacific alliances, questions remain as to the sustainability of these trends. With its emphasis on multilateralism and a global struggle between democracy and autocracy, the Biden administration has encouraged cross-regional cooperation between U.S. allies in Europe and the Indo-Pacific, and pursued a “latticework” strategy in the Indo-Pacific so as to meet the challenges posed by China and North Korea. In Europe, the first Trump administration encouraged greater bilateralism, while urging NATO and individual allies to take China more seriously. For its part, the Biden administration has continued to push for greater trans-Atlantic coordination on China while pushing for a revival of multilateral cooperation through NATO and greater U.S.-E.U. ties.

As a second Trump administration takes office in January 2025, a significant recalibration of U.S. global priorities and policies may affect the way in which cooperation among U.S. allies takes shape. Trump’s instinct may be to favor bilateral cooperation over minilateral and multilateral initiatives, as his first term in office attests to. Trump may also be less inclined than Biden to foster cross-regional linkages. Moreover, a more decisive focus on the China threat in the Indo-Pacific (as opposed to Biden’s efforts to cast China as a global and normative challenge) could lead the incoming Trump administration to de-prioritize Europe and tell Europeans to focus squarely on their own region.

That said, a China-centric focus on the part of the Trump administration could also incentivize further cross-regional cooperation among U.S. allies. After all, the United States put much emphasis on getting NATO and Europeans to take China seriously already during Trump’s first administration. Moreover, many of the cross-regional processes that have been put in place over the last few years will have their own bureaucratic rhythm, which may incentivize a second Trump administration to find ways to leverage them as it focuses on competition with China. Besides, a not-insignificant share of cross-regional initiatives takes place with limited or no U.S. involvement, including the next-generation fighter jet program between the United Kingdom, Japan, and Italy; the bilateral cooperation taking place between South Korea and Poland or Romania; or the Indo-Pacific outreach by France, the United Kingdom, and Germany. In fact, America’s European and Indo-Pacific partners may seek greater spoke-to-spoke and cross-regional connections as a way to mitigate Trump-related abandonment concerns and transactional approach to alliances.

An “America First” policy could thus cut two ways for alliance networking. On the one hand, it may undermine cooperation amongst U.S. allies within and across regions, as a result of a focus on bilateralism and regional tradeoffs. On the other, its emphasis on competition with China could incentivize the Trump administration to look for ways to leverage within- and cross-regional networking, even if emphasizing bilateralism and U.S. centrality. Yet given the structural drivers underpinning the transformation of intra- and cross-theater alliance cooperation, the alliance networking in Europe and Asia may well be here to stay.

Lotje Boswinkel is a Ph.D. researcher at the Centre for Security, Diplomacy and Strategy at Vrije Universiteit Brussel, a non-resident associate fellow at NATO Defense College, and a Hans J. Morgenthau fellow at the Notre Dame International Security Center.

Prof. Luis Simón is director of the Centre for Security, Diplomacy and Strategy at Vrije Universiteit Brussel, and director of the Brussels office of the Elcano Royal Institute.

Alexander Lanoszka is an assistant professor of international relations in the Department of Political Science and the Balsillie School of International Affairs at the University of Waterloo. 

Hugo Meijer is CNRS Research Fellow at Sciences Po, Center for International Studies, Deputy Director for Scientific Affairs, and the Founding Director of the European Initiative for Security Studies.

This paper was completed with the support of the NATO Science for Peace and Security Programme. It is part of a project looking at the future of the Indo-Pacific region and NATO, and the authors wish to thank the participants of a conference organized under the project on February 9, 2024 in Paris, France, which was hosted by Sciences Po.

Image: The European Commission via Wikimedia Commons.

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