This chapter zooms in on the hardware of the U.S.-led international order. I argue that such order rests on a geostrategic trinity: “command of the sea,” and the other global commons (i.e., airspace, outer space and cyber-space), and the preservation of favorable balances of power in East Asia and Europe. These three elements are linked. Command of the commons is critical to the effective projection of military power onto Europe and East Asia, as well as to the preservation of favorable balances in those two regions. In turn, such favorable balances help keep at bay those great powers that may otherwise be in a position to challenge command of the commons.

This chapter will first discuss the link between the U.S. and its allies’ power and the institutions that underpin the international order, and discuss how the rise of China and the competitive turn in international politics are leading to greater contestation of that order. I will then unpack the material foundations underpinning the U.S.-led order: command of the commons and the preservation of favorable balances in Europe and East Asia. This chapter will conclude with some reflections about the relative importance of Europe and Asia in the context of China’s rise and the current war in Ukraine.

A U.S.-Led International Order

In his seminal work Liberal Leviathan, G. John Ikenberry makes a fairly intuitive point: international orders, norms, and institutions reflect power balances—they are created and maintained by powerful states or coalitions forming around them.Footnote 1 Indeed, ongoing debates around the international order’s allegedly “liberal,” “open” or “global” nature often gloss over its most important and defining attribute: it is, first and foremost, a U.S.-led order. As I argue below, “U.S.-led” arguably makes for a more accurate description of the current international order than simply “American,” in that the order is led but not owned by the United States, or at least not fully. Other powers, particularly U.S. allies, are co-tenants, and the order’s sustainability requires their active participation.

After World War II, the United States and its allies set out to develop a set of interconnected global and regional institutions aimed at “locking” their geopolitical gains.Footnote 2 Some of those institutions were rather inclusive, the United Nations (U.N.) system being arguably the best example—even though its security council was restricted to great powers, it included all the remaining ones, including America’s main geopolitical competitor (the Soviet Union).Footnote 3 Others have been more exclusive, however. The so-called Bretton Woods institutions (i.e., International Monetary Fund, World Bank, and General Agreement on Trade and Tariffs, later renamed World Trade Organization), which form the backbone of the international economic order, excluded many countries for a long time (including Russia and China), and afforded the United States and its allies (mainly Western Europeans and Japan) a position of institutional and normative primacy. Even more exclusive was the so-called regional layer of the international order, with the critical regions of Europe and East Asia structured around U.S.-led alliances (NATO and the hub-and-spokes system respectively) or U.S.-sponsored institutions (like the European Community).

U.S. geopolitical and security interests were thus in sync with an international order which, by and large, excluded the Soviet Union and its satellite countries, and proved instrumental in cementing U.S. economic and political ties with key countries in the European and East Asian rimlands. The international order was therefore not neutral in power-political terms. It reflected U.S. and its allies’ interests, and was strategically leveraged by the United States in its long-term strategic competition with the Soviet Union.

The collapse of the Soviet Union cleared the path for the progressive “globalization” of the U.S.-led order from the early 1990s onwards. That was illustrated by the integration of Central and Eastern Europe, Central and South Asia, Southeast Asia, and parts of the Middle East into many of the institutions that embodied the order—and even also that of Russia and China, however fragile or selective such integration may have turned out to be. While this may have given some the impression that the order’s globalization was neutral in power-political terms, it was not: it was underwritten by the U.S. and its allies’ power all along.Footnote 4

From the 2010s onwards, scholars and policy-makers have begun to debate to what extent the return of great power competition—and more precisely China’s rise and America’s (alleged) relative decline—may impinge on the structure of the international order.Footnote 5 Rising powers (notably China) have consistently argued that some of the order’s flagship institutions—like the International Monetary Fund, World Bank, or World Trade Organization—should be reformed to reflect new political realities. In parallel, they have sponsored new institutions designed to their image, such as the Belt and Road Initiative or the Asian Infrastructure Investment Bank. This has spurred much debate as to whether the international order has become increasingly contested or rather that there are various, overlapping orders.

How did the United States and its allies manage to get such a commanding position in the post-war international order in the first place? How can they defend such position in an increasingly competitive context?

The Order’s Hardware

Scholars have written extensively about the importance of sea power in international politics.Footnote 6 The sea—and more specifically the high seas—is the first and arguably most important of the so-called “global commons,” i.e., those spaces that belong to no one and provide access to much of the world.Footnote 7 Command of the sea affords a great power the ability to move freely in peacetime and wartime, deny such freedom to relevant competitors, and effectively project military power on land worldwide. In Paul Kennedy’s words, command of the sea allows one to exercise “influence at a global rather than a purely regional level.”Footnote 8 Conversely, forward force deployments and alliances have traditionally allowed sea powers to undergird favorable balances of power in key continental environments, thus holding potential challengers at bay.Footnote 9

Over the past three centuries, those great powers who have exercised command of the sea have played a key role in structuring the international order—first the United Kingdom and later the United States.Footnote 10 Command of the sea allowed the United States to achieve the following: to project overwhelming military power into Europe and East Asia during World War II; to permanently supply forwardly deployed forces and articulate alliances in those two regions during the Cold War; to keep great power competitors away from the Western Hemisphere; and, project military power worldwide. Arguably, by ensuring a strategic edge over potential competitors, command of the sea helped set the foundations for U.S. command of the other global commons (air, space, cyber-space).Footnote 11

Whilst command of the sea may indeed afford the United States a global strategic outlook, Europe and East Asia have traditionally held the pride of place for Washington.Footnote 12 Outside of North America, these two regions harbor the greatest concentration of wealth, industrial, technological, and military power in the world. If another great power managed to dominate either region, it would be in a position to directly challenge U.S. command of the sea. Therefore, preserving favorable balances of power in Europe and East Asia, and Washington’s historical commitment to lasting alliances and forward military presence in both regions remains important.

Command of the sea and the preservation of a favorable continental balance in Europe go hand in hand. U.S. and its allies’ supremacy over the main maritime approaches to the European continent—namely, the Atlantic Ocean, the Baltic and Mediterranean seas—provide the foundation for U.S. forward presence in Europe through a regional network of bases and alliances, whose main institutional manifestation is NATO. Such alliances and bases are critical to the preservation of a favorable balance in Europe. Conversely, a favorable continental balance is the best way to hold prospective challengers at bay, safeguard U.S. and allied command over the continent’s maritime approaches and, ultimately, command of the sea. The logic cuts both ways.

A somewhat similar logic applies to East Asia. The U.S. and its allies’ supremacy over the main maritime approaches to the East Asian rimland (i.e., through Singapore, the Philippines, Taiwan, the Ryukus and Japan’s main islands) has been the foundation of forward presence in the region since World War II. Japan stands out, however, as the regional hub of the U.S. Air Force and Navy, including the Marine Corps. Australia, which provides a secure geostrategic rear, is likely to become increasingly central to U.S. force posture in the region if China’s Anti-Access and Area Denial (A2AD) capabilities continue to threaten U.S. positions in north- and south-east Asia. U.S.-led alliances and bases are thus also critical to the preservation of a favorable balance in East Asia. Conversely, preventing the emergence of a regional hegemon is the best way to safeguard the U.S. and its allies’ superiority in the Western Pacific. This is why China’s A2/AD threat within the first island chain poses such a fundamental strategic challenge, as it threatens U.S. allies and forward operating bases, upon which both a favorable regional balance and command of the commons rest.Footnote 13

The relationship between the United States and its Euro-Atlantic and Indo-Pacific allies is symbiotic. U.S. allies in Europe and East Asia have played a particularly important role in upholding favorable balances in their respective regions. In doing so, they help free up U.S. resources and bandwidth, affording Washington greater global strategic flexibility. They also regularly support U.S. diplomatic initiatives and operations beyond their home regions, and are actively engaged in many of the institutions that underpin the international order. Moreover, their interoperability with the United States in the naval, air, space and cyber domains allows them to contribute to command of the commons. All in all, the capability and legitimacy provided by allies helps makes the U.S.-led order stronger and more sustainable.

To be sure, whilst America’s Indo-Pacific and Euro-Atlantic allies may indeed contribute to the overall stability of the U.S.-led order, the bulk of their contribution revolves around their respective regions. There is indeed much debate around the fact that NATO and the hub-and-spokes alliances are first and foremost regional alliances, and have little to do with U.S. alliances or activities elsewhere.Footnote 14 An important strand of work also focuses on how Indo-Pacific and Euro-Atlantic allies even compete for U.S resources, and how the United States should prioritize between both regions and sets of alliances.Footnote 15

Discussions about regional tradeoffs and priorities are by no means irrelevant. Yet, they often overlook the fact that there is a degree of geostrategic interdependence between the Euro-Atlantic and Indo-Pacific regions, not least considering their security architectures revolve around the same factor (U.S. power), and that U.S. strategic resources are finite.Footnote 16 Ultimately, the unraveling of the balance of power in one region would punch a hole in the U.S.-led forward defense perimeter in Eurasia, endanger command of the sea, and eventually threaten the balance in the other region, thus forcing the United States to redeploy its assets accordingly. This means that, even if the direct concern of U.S. allies in the Euro-Atlantic and Indo-Pacific is with the preservation of favorable balances in their respective regions, they also have an indirect but nonetheless important stake in the preservation of favorable balances in each other’s region, and command of the commons more broadly. It also means that America’s adequate management of the international order requires calibrating its engagement in both regions and in the commons.

One thing, however, is to acknowledge that there is a degree of interdependence between geostrategic dynamics in the Euro-Atlantic and Indo-Pacific, and quite another to ascertain how interdependent these two regions actually are, or how that interdependence should affect U.S. and allied strategy. Thus, for instance, if a revisionist power were to upend the balance of power in Asia and contest U.S. command of the commons, it would still take time before the U.S. and its Euro-Atlantic allies lost command over the maritime approaches to Europe, let alone lose their favorable position in Europe. Yet, the bulk of U.S. strategic resources and attention would need to be diverted towards Asia. This could eventually leave Europe unguarded, and offer revisionist great powers in that region a window for opportunistic revision. The extent to which the United States is willing to take that risk hinges on two factors: the nature of the challenge in Asia, and the nature of the (latent) challenge in Europe. Admittedly, if we assume that the balance in both regions is structurally delicate and requires permanent U.S. engagement, then the United States should be wary of over-prioritizing one region at the expense of the other. To what extent, however, does that assumption hold? In other words, how fragile actually are the regional balances in Europe and East Asia?

As already argued, the strategic importance of East Asia and Europe is justified by the fact that they are the only two regions that harbor the demographic, industrial, technological, and military potential to seriously challenge the U.S. and its allies’ superiority at sea and over the other global commons. This has generally been the case since World War II, which led the United States to intervene in both regions simultaneously. Ever since, the need to prevent a simultaneous two-front attack in those key regions has been a core driver of U.S. grand strategy. Yet, the relative importance of each region has varied over time, as has their degree of geostrategic interdependence.

Most scholars and experts would agree that Europe was the center of gravity of both U.S. geostrategy and the U.S.-led international order during the Cold War. The international order was by and large subordinated to Europe because that region was the center of gravity of great power (i.e., U.S.-Soviet) competition. The Soviet Union’s permanent deployment of hundreds of thousands of military forces across Central Europe represented an acute and persistent threat to the European balance, all the while Soviet communism enjoyed significant levels of societal support across Western Europe. No equivalent threat existed in Asia. China was economically weak, and focused inwards. In fact, it was the Soviet Union itself that was considered the main regional threat in East Asia. However, its relative lack of military forces in the region and long lines of internal communications meant the Soviet Union was more of a strategic nuisance rather than an actual—let alone comprehensive—threat to the East Asian regional balance.

Today’s situation shows a reversal. In Asia, a rising China poses a serious and comprehensive (i.e., military, economic and political) threat to the regional balance. In Europe, NATO and the U.S. system enjoy a surplus of geostrategic depth, thanks in large part to the gains of the post-Cold War years. Russia’s power is a fraction of that of the Soviet Union. Its only strength is military power, and even that has been questioned recently. Even though it may be premature to draw too many lessons from Russia’s performance in Ukraine, its seeming difficulties to hold on to its early gains in eastern Ukraine raises questions about its ability to even pose a conventional military threat to NATO, let alone a cross-cutting (i.e., political, economic, and military) threat to the European balance of power. This is even truer in light of Russia’s growing economic and political isolation, and NATO’s increasing geostrategic depth on the continent, as availed by eastern enlargement and, more recently, the “de-finlandization” of Sweden and Finland. If anything, the war in Ukraine may be reinforcing the assumption that the preservation of a favorable balance in Europe is not at risk, even if stability in Eastern Europe is. The same cannot be said of East Asia.

For one thing, China’s military modernization and assertiveness has improved its regional military position vis-à-vis the United States, and challenged America’s ability to freely access and move within the Western Pacific theater of operations unimpeded. Notably, the facts that China’s territory hugs much of the Western Pacific, and the U.S. led defense perimeter in East Asia has little depth (unlike in Europe), puts China in a position to project its power to the high seas, and the commons more broadly. For another, many countries in East Asia are part of China’s economic orbit, and value their political relationship with Beijing. Thus, whilst Russia is increasingly isolated in Europe politically and economically—and its ability to threaten NATO conventionally is increasingly questioned—China is making a serious and comprehensive (economic, political, and military) bid for regional hegemony in East Asia, and has the geostrategic standing and resources to venture into the high seas, and confidently push back against the U.S. and its allies’ command of the global commons. Thus, the link between command of the commons and a favorable balance of power in East Asia has arguably become the key to the international order’s fate.

The relative importance between Europe and East Asia is not the only factor that has changed and may have implications for the fate of the U.S. led international order. Another relevant change relates to the degree of interdependence between both regions, which was relatively low during the Cold War, and is comparatively higher today. This point may sound counterintuitive—indeed, the fact that the Soviet Union was perceived as the main threat in both Europe and East Asia apparently underscored the geostrategic interdependence between both regions during the Cold War. However, that point actually accounts for the low degree of geostrategic interdependence between the two regions back then. This is because if the United States felt it had to step up its contribution to one region (e.g., Europe) in response to a perceived increased Soviet threat therein, neither Washington nor its allies in the other region would need to worry too much about disattending the other region. After all, Soviet resources were also limited, and a Soviet prioritization of Europe would automatically limit Moscow’s strategic bandwidth in East Asia. The sense of geostrategic tradeoffs between both regions and sets of U.S. allies was therefore less acute.

Today, the fact that the United States faces two different great power challengers in two different regions actually underscores the interdependence between both theaters, given the growing relevance of tradeoffs in the context of U.S. force posture and structure. After all, the main factor bringing both regions together is the fact that their respective balances hinge on the same factor (U.S. power). The prospect for endemic instability in Europe, Washington’s pre-existing commitments in that region, and growing cooperation between China and Russia, do underscore the interdependence between both theaters. Moreover, the presence of first-rate allies still gives Europe a systemic importance that no other regions (other than East Asia) have. Yet, it is arguably a diminishing importance.

To sum up, it now can be argued that while the United States and its allies have faced a balance of power challenge in both Europe and East Asia, they may face a stability problem in the former and a balance of power problem in the latter. That puts the latter region on a higher level strategically. Tellingly, even though U.S. national security documents still refer to both China and Russia vaguely as strategic competitors, the former is increasingly seen as a region-wide and even global challenge, and the latter as a challenge to its immediate neighbor. As recently argued by U.S. Deputy Secretary of Defense Kathleen Hicks, Russia is the “acute threat” (i.e., sharp, near term and potentially more transitory); China the ‘pacing challenge’ (“that can bring together a comprehensive suite of power”).Footnote 17 This distinction is not minor: Moscow can threaten U.S. allies in Eastern Europe but is not in a position to upset the European balance of power, let alone the global one. Yet, China can. From this viewpoint, Russia poses a stability problem in part of Europe, but poses no real challenge to the trinity, in that it cannot upset any of its core foundations (i.e., the regional balance in Europe or the global commons). China, for its part poses a threat to two of the key foundations of the trinity.

Arguably, the shift in the relative geostrategic importance of Europe and East Asia today seems to resemble the post-Tsushima dynamic in the early twentieth century. Following its defeat in the far east in 1905, Russia was de facto neutralized, thus clearing the way for Britain to redirect its resources against the one power that could comprehensively challenge the continental balance in Europe and command of the sea (Germany).

What does this mean for U.S. and allied strategy going forward?

In light of the current war in Ukraine, U.S. Secretary of Defense Lloyd Austin has recently argued that the United States “wanted to see Russia weakened to the degree that it can’t do the kinds of things that it has done in invading Ukraine.”Footnote 18 The relevance of such comments transcends Europe proper. By substantially weakening Russia, the existence of a threat to the European balance could be neutralized for the foreseeable future. That, in turn, could conceivably allow the United States to redirect the bulk of its strategic attention towards the pacing challenge, i.e., China’s concomitant threat to the East Asian balance and command of the sea.

There has been much debate recently about how America’s Indo-Pacific allies have shown solidarity with Euro-Atlantic ones in light of Russia’s invasion of Ukraine. This is welcomed by Europe. However, solidarity is a two-way street. As the link between the East Asian balance and command of the commons clearly emerges as the center of gravity of the international order, Euro-Atlantic engagement in the Indo-Pacific will become comparatively more important strategically than Indo-Pacific engagement in the Euro-Atlantic. Seen through this lens, the Euro-Atlantic allies should avoid the trap of overpreparing to fighting the last war in continental Europe, and think more seriously about how they may contribute to deterring a future war in East Asia and to the preservation of command of the commons. Otherwise, they would be abandoning the first line of international politics, and devoting their energies to stabilizing a secondary region without having the ability to influence the broader systemic dynamics that encompass that very region.