This piece was originally published in The Center for Strategic & International Studies (CSIS)
Executive Summary
This report examines the emerging opportunities and structural constraints of cross-theater defense industrial cooperation between Euro-Atlantic and Indo-Pacific allies in an era of protracted great power competition and “precise mass” warfare. While these regions have traditionally been treated as distinct strategic theaters, the report argues that they now confront a converging operational challenge: implementing deterrence by denial against nuclear-armed adversaries employing anti-access/area-denial (A2/AD) strategies and large-scale attrition. Drawing on lessons from Ukraine, the Middle East, and Indo-Pacific contingency planning, the analysis highlights a systemic shift away from reliance on small numbers of exquisite platforms toward scalable, attritable, and networked capabilities. The report assesses Europe’s rapid but uneven defense industrial rearmament, contrasts it with U.S. technological leadership and Indo-Pacific strengths in maritime and electronics manufacturing, and identifies complementarities across allied industrial bases. Three alternative models for cross-theater cooperation—bifurcation, cooperation, and integration—are evaluated, before advancing a logic of selective alignment based on standardization versus regional customization. The report concludes that a selectively integrated deterrence ecosystem centered on fungible capabilities, shared standards, and coordinated surge capacity offers the most politically feasible and strategically effective path for strengthening allied denial strategies across both theaters.
Introduction
The Euro-Atlantic and Indo-Pacific regions are often treated as separate strategic theaters, each with its own geography, operational demands, and threat environment. NATO’s emphasis on deterring a Russian attack on Europe has led to a focus on land warfare and air superiority. In turn, as the United States and its Indo-Pacific allies have focused on thwarting China’s bid for regional primacy, they have prioritized the maritime—and air—domains.
Beneath these differences, however, lies a growing convergence. U.S. allies across both regions actually face a remarkably similar operational problem: how to implement deterrence by denial against nuclear-armed great power challengers intent on constraining U.S. access, achieving local escalation dominance, and reshaping regional orders to their advantage. This emerging symmetry is not simply conceptual but is reshaping force planning, operational concepts, and defense industrial priorities.
Lessons from the war in Ukraine, the use of autonomous systems across the Middle East, and the rapid evolution of Chinese—and Russian—A2/AD networks are accelerating a shift away from reliance on small numbers of exquisite, high-end systems toward a model in which precision must be paired with mass. Operational concepts such as “hellscape” in the Indo-Pacific, and initiatives such as Replicator in the United States, similarly reflect a recognition that attritability, volume, speed of production, and autonomous behavior are becoming core features of modern warfare.
At the same time, the return of Donald Trump to the White House, Washington’s prioritization of the Indo-Pacific, and the growing stresses on U.S. defense industrial capacity have revived long-standing questions about burden sharing and the ability of the United States to deter or fight two major regional conflicts simultaneously. The 2026 U.S. National Defense Strategy frames this as a “simultaneity problem,” whereby allied capacity—not only U.S. military power—must underpin credible deterrence across multiple theaters. Against this backdrop, U.S. allies and adversaries alike increasingly assume that, in a crisis, Washington may struggle to fully resource two theaters at once. How U.S. allies prepare for this simultaneity problem—and how they structure their defense industrial cooperation accordingly—may prove decisive for the future of deterrence in both the Euro-Atlantic and Indo-Pacific.
The challenge today is not merely whether Euro-Atlantic and Indo-Pacific allies should cooperate more deeply in the defense industrial domain, but where such cooperation makes sense, how far it should go, and what form it should take. Such alignment is unlikely to involve routine cross-theater operational engagement, which remains politically constrained; rather, the most promising avenues lie in defense industrial and technological cooperation, and the sharing of concepts and standards. Although geography, adversaries, and geostrategic priorities differ, the fundamental requirements of denial—long-range strike, air and missile defense, autonomous systems, ammunition depth, resilient networks, and surge capacity—are increasingly shared. This creates real opportunities for cross-theater cooperation but also reveals structural pitfalls that must be carefully managed.
Meaningful defense industrial alignment across the Euro-Atlantic and Indo-Pacific is both possible and desirable, but must be selective rather than indiscriminate. Certain capabilities lend themselves more naturally to cooperation or even integration, especially those that benefit from economies of scale and shared standards. Others are so sensitive, region-specific, or technologically complex that cooperation may be difficult, counterproductive, or politically untenable. A nuanced approach—one that distinguishes between areas requiring customization and those that can be standardized—is thus essential.
Converging Operational Demands: From Boutique Precision to Precise Mass
The wars of the 2020s have exposed the limits of Western militaries’ two-decade reliance on high-end, low-volume systems optimized for permissive environments. In Ukraine, both sides are expending artillery and drones at staggering rates, and missile barrages number in the thousands. Recent U.S. and Israeli operations against Iran have likewise highlighted the rapid burn rates associated with precision-guided munitions in high-intensity campaigns, reinforcing concerns about the sustainability of existing stockpiles. Meanwhile, Indo-Pacific scenarios increasingly assume attrition levels far exceeding previous planning assumptions. In this vein, the “hellscape” concept in the Indo-Pacific refers to the deliberate saturation of contested spaces with large numbers of attritable, autonomous, and networked systems designed to impose overwhelming complexity and cost on an adversary from the outset of a conflict. Rather than relying on a small number of exquisite platforms, the aim is to flood the battlespace with distributed sensors, shooters, and decoys that degrade, confuse, and exhaust enemy forces. This approach reflects a broader shift toward deterrence by denial through volume, resilience, and sustained attrition rather than technological superiority alone.
These experiences underscore a broader shift toward “precise mass,” where precision remains essential but is no longer sufficient in isolation. Modern warfare now demands a blend of scalable, attritable capabilities; flexible, software-driven architectures; resilient, multilayered networks; and the industrial capacity to sustain operations over time, reflecting a broader shift toward industrial mobilization and surge production as central elements of deterrence. Whether in the Baltic region or the First Island Chain, denial strategies hinge on the ability to rapidly impose costs, complicate adversary planning, and blunt early offensives.
Across both theaters, long-range fires, air and missile defense, and autonomous systems stand at the forefront of this shift. Countries in Europe are investing in deep precision strike capabilities at an unprecedented scale, while Indo-Pacific allies focus on anti-ship, anti-air, and anti-access capabilities. Both are also accelerating the adoption of drones, unmanned maritime platforms, electronic warfare tools, and software-defined battle networks. The result is a striking alignment in the kinds of capabilities that denial requires, even as operational environments differ.
This convergence lays the groundwork for deeper industrial cooperation between the United States and its Indo-Pacific and Euro-Atlantic allies. Yet the ability to produce these capabilities at scale is lagging behind demand, particularly in Europe, where decades of deindustrialization and just-in-time production have left governments scrambling to rebuild lost capacity. This industrial challenge is now one of the central factors binding the Euro-Atlantic and Indo-Pacific theaters together.
Europe’s Defense Industrial Awakening—and Its Persistent Limits
Europe’s rapid rearmament in response to Russia’s war against Ukraine has revealed both impressive momentum and significant structural weaknesses. Perhaps the most consequential shift concerns long-range strike, which has moved from a niche capability to a central element of European deterrence. Yet efforts to field such systems have been hindered by long-standing industrial constraints. Missile manufacturers have historically produced in small batches, often shutting down production lines for years at a time, while key technologies—such as turbofan engines for extended-range cruise missiles—remain dependent on U.S. suppliers. Even collaborative European projects are unlikely to deliver new capabilities in the short or medium term.
At the policy level, governments face a dilemma. The urgency of deterrence pushes them toward rapid procurement from U.S. and non-European suppliers, while strategic aspirations push them toward greater industrial autonomy. Recent shifts in procurement policy illustrate this tension. Some states have publicly prioritized European or national origin for major defense purchases, yet continue to buy from abroad when speed is paramount. A similar pattern is unfolding along Europe’s eastern flank, where countries have turned to South Korean suppliers for rapid deliveries of critical systems.
Europe’s ammunition and missile production capacity has begun to scale, but remains insufficient for a protracted high-intensity conflict. EU initiatives, new financial instruments, expanded framework contracts, and efforts to attract new entrants represent important steps toward rebuilding defense industrial depth. In parallel, European policymakers are exploring ways to integrate Ukrainian know-how—particularly in low-cost drones and rapid adaptation—into their emerging industrial architecture. Yet there remains a risk of overcorrecting toward cheap unmanned systems at the expense of the high-end capabilities necessary for deterrence against Russia.
The broader challenge for Europe is to combine its growing political will and financial investments with structural reforms that enable sustained production at scale. Without these reforms, its ambitions for autonomy will remain limited, and its ability to contribute meaningfully to cross-theater burden sharing will fall short.
Differentiated Strengths Across the Euro-Atlantic and Indo-Pacific
While both theaters face similar operational demands, their defense industries possess different strengths that can create opportunities for meaningful cross-theater synergy. Europe is rapidly becoming a global leader in the production of artillery, ammunition, and certain classes of mid-tier missiles. Its ability to repurpose civilian industrial capacity—particularly in the automotive sector—has enabled a rapid increase in shell and rocket production. Some European firms now outproduce their U.S. counterparts in key munitions.
By contrast, the United States maintains a significant lead in advanced missile systems, propulsion technologies, sensing, software, and networked command and control. Meanwhile, Indo-Pacific allies—especially Japan and South Korea—possess world-class shipbuilding capacity, high-quality maritime missile programs, and advanced electronics and dual-use technologies.
These differentiated strengths suggest that cross-theater cooperation need not involve identical contributions. Instead, the most effective approach may be a division of labor in which Europe specializes in the scalable production of ammunition and mid-tier missiles, the Indo-Pacific anchors shipbuilding and maritime strike, and the U.S. concentrates on the high-end enabling systems that bind these networks together. This kind of specialization is far more realistic than attempts to create a single, monolithic industrial ecosystem in which all allies produce the same capabilities. This logic increasingly mirrors U.S. strategic thinking, which assumes that allies will take primary responsibility for regional defense while U.S. forces provide selective enablers rather than acting as the default backbone of every theater.
Three Models for Structuring Cross-Theater Cooperation
As allies consider how to reconcile region-specific demands with shared strategic challenges, three conceptual models help illuminate possible approaches.
The first is bifurcation, a model in which the Euro-Atlantic and Indo-Pacific theaters are treated as distinct, with separate industrial strategies, separate threat hierarchies, and minimal cross-regional cooperation. This approach has the advantage of clarity and regional focus, but amplifies vulnerabilities elsewhere. It risks replicating production lines, missing economies of scale, and exacerbating the challenge the United States faces in supporting two theaters simultaneously. It is also inconsistent with the operational convergence described earlier.
A more flexible, cooperative approach treats the two theaters as regionally distinct but strategically intertwined. Under this approach, each region focuses on its primary challenges—Europe on Russia, the Indo-Pacific on China—while pursuing deeper industrial and technological cooperation to exploit synergies and mitigate the United States’ simultaneity concerns. This could include codevelopment and coproduction projects, cross-licensing agreements, harmonized standards, and shared stockpiles for fungible capabilities. Maritime and aerospace programs such as AUKUS Pillar II or multinational air-combat initiatives illustrate elements of this logic. It strikes a balance between autonomy and interdependence, reinforcing cross-theater industrial and technological alignment while leaving operational engagement largely regionally focused.
A third model is integration—i.e., treating the Euro-Atlantic and Indo-Pacific as a single strategic theater. This would involve shared operational concepts, unified standards, integrated industrial planning, and more structured and permanent cooperation in emerging technologies. The industrial goal would be a genuinely cross-theater deterrence ecosystem, with interoperable architectures and interchangeable munitions and systems. While the technological incentives for such integration are strong—particularly for autonomous systems, open architectures, and AI-enabled command and control—the political, legal, and institutional barriers remain formidable.
Customization, Standardization, and the Logic of Selective Cooperation
A crucial factor in determining which capabilities lend themselves to cross-theater cooperation is the degree to which they require customization for regional conditions versus the degree to which they can be standardized across multiple environments. Long-range anti-ship missiles designed for the Western Pacific’s maritime geography, for example, must account for vastly different operational requirements than land-attack missiles optimized for European terrain. Similarly, air and missile defense systems may require integration with theater-specific sensor networks, political constraints, or rules of engagement. The more denial strategies are shaped by specific geographic conditions—whether the Baltic approaches, the High North, or the First Island Chain—the greater the premium on customized operational design even as industrial standardization remains attractive.
By contrast, mid-tier missile systems, artillery, drones, software-defined radios, and open-architecture battle networks generally require far less regional customization. Their fundamental design principles are broadly applicable across theaters, and their operational utility can employ generic, common specifications. This makes them ideal candidates for standardization and joint production. Ammunition exemplifies the same logic: A 155 mm round used in the Baltics is functionally identical to one used in the Western Pacific, and therefore benefits enormously from pooled production.
Understanding this distinction between capabilities requiring high levels of customization and those amenable to standardization is essential for avoiding failed cooperation efforts. It allows policymakers to prioritize industrial collaboration where it is both feasible and strategically valuable, rather than pursuing cooperation for its own sake.
Toward a Cross-Theater Deterrence Ecosystem
The converging operational demands facing Euro-Atlantic and Indo-Pacific allies, combined with their differentiated industrial strengths, point toward the emergence of an interconnected, cross-theater deterrence ecosystem. This ecosystem need not be fully integrated to be effective. What matters is creating shared standards for key enablers; flexible, modular architectures for allies to plug in capabilities; and coordinated industrial planning for systems that benefit most from economies of scale. Joint research on emerging technologies—especially artificial intelligence, missile defense, and space-based sensing—can bind the two theaters’ innovation pipelines together. And cross-licensing, codevelopment, and shared surge capacity can create redundancy and resilience.
Such an ecosystem mitigates the simultaneity problem: the risk that, in a major crisis in one theater, the United States might struggle to adequately resource the other. It also allows allies to exploit their complementary industrial strengths while reinforcing their region-specific strategies. Focusing on fungible capabilities—mid-tier missiles, ammunition, autonomous systems, and software-defined enablers—creates the foundation for credible denial in both regions.
The alternative—a fragmented industrial landscape, mismatched standards, and insufficient production capacity—would impose costs on deterrence and leave U.S. allies vulnerable to shocks and supply chain disruptions. In an era of protracted, attritional, and technologically dynamic warfare, the ability to produce together may increasingly determine the ability to deter together.
Conclusion
The Euro-Atlantic and Indo-Pacific theaters are entering an era in which defense industrial policy is as central to deterrence by denial as force posture or readiness. Allies face a shared operational problem, and the wars of the present decade have made clear that denial requires not just capability but mass, not just innovation but scale, not just exquisite systems but adaptable and affordable ones. The convergence of strategic requirements across Europe and Asia creates meaningful opportunities for cross-theater collaboration—but only if pursued selectively and with recognition of the existence of differences in each operational environment.
A balanced approach, rooted in the recognition that not all systems warrant the same degree of cooperation, offers the most effective way forward. By focusing on those capabilities that benefit from standardization and economies of scale—while allowing for customization where regional geography demands it—the United States and its European and Indo-Pacific allies can build an industrial foundation for deterrence that is both resilient and politically feasible.
In a world where the United States may be stretched thin and adversaries increasingly coordinate across regions, the ability of allies to reinforce each other through industrial cooperation will matter more than ever. Deterrence by denial will depend not only on strategy and force design, but on whether Euro-Atlantic and Indo-Pacific partners can produce the right capabilities, at the right scale, at the right time. The future of both theaters may hinge as much on what happens in factories and supply chains as on what happens on the battlefield.
Luis Simón is a senior associate (non-resident) with the Europe, Russia, and Eurasia Program at the Center for Strategic and International Studies. He is the director of the Centre for Security, Diplomacy and Strategy at the Vrije Universiteit Brussel and the Brussels office of the Elcano Royal Institute.
This report is made possible by general support to CSIS. No direct sponsorship contributed to this report.
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