US Defense Policy and Strategic Guidance for a Multi-Theater Military

Today, the ambition of US grand strategy exceeds the US military’s ability to support it.

The United States seeks to sustain deterrence and secure its interests across three key regions: Europe, the Indo-Pacific, and the Middle East. However, it seeks to do so without the margin of military, economic, or technological superiority it previously enjoyed. Despite the previous two administrations’ efforts to set a new direction for US defense policy and strategy, the Department of Defense (DOD) has yet to effectively respond with the urgency, ambition, and imagination required. Congress has made the problem worse, saddling the US military with more than a decade of budgetary malpractice marked by continuing resolutions, sequestration, insufficient growth, and perpetual uncertainty.

The result is that the US military is in danger of becoming—if it hasn’t already—a one-war military. Under plausible scenarios, that one war could be lost to China. At the same time, overlapping conflicts in Ukraine and the Middle East and the emergence of a nascent axis of aggressors have highlighted the risk of simultaneous conflicts in multiple theaters.

The United States needs to rebuild a multi-theater military—one that is capable of defending US interests across three key regions, prepared for simultaneous conflicts, and equipped with cutting-edge technologies fielded at scale. But how?

One thing a multi-theater military clearly needs is more. More capacity in key capability areas like munitions, long-range fires, integrated air and missile defense, contested logistics, undersea warfare, and persistent intelligence, surveillance, and reconnaissance (ISR). More production from the defense industrial base in peacetime and wartime. More people in the military and the defense industrial base with the right mix of education and skills. And more money, as DOD spending as a percentage of gross domestic product (GDP) is roughly half what it was during the major defense modernization 40 years ago.¹

If only it were so simple. In reality, how to build a multi-theater military comes down to much more difficult issues, such as summoning political will to make tough and controversial decisions; organizing and managing one of the world’s largest bureaucracies; developing feasible theories of victory against nuclear-armed adversaries; determining the proper mix of force structure for conflicts of uncertain scale, scope, and duration; sequencing investments over time; and prioritizing among theaters.

This chapter does not address all these issues in full. But it provides recommendations for US defense policy and strategy to move the joint force toward becoming a multi-theater military. These include changes in DOD force planning, contingency planning, concept development and force design, budget and force development, and posture and force employment.

The US military has real problems in an increasingly dangerous world. But it must rise to master these challenges without despair and without delay.

Alternatives to a Multi-Theater Military

Since the Cold War era, building and maintaining a US military capable of winning wars in multiple theaters has been an uncontroversial objective. No more. As the United States’ adversaries have grown stronger, Washington’s policy failures have allowed US military power to dangerously erode, leaving the joint force capable of fighting only one war at a time. Confronted with this difficult reality, some experts have asserted that a return to a multi-theater military would be too expensive, too slow, or downright impossible. According to this view, DOD should pursue one or more strategic alternatives for meeting its objectives.

The United States could prioritize by narrowing the objectives of its defense strategy and adopting a single-war force-planning construct. Proponents of this form of prioritization worry that attempts to pursue a multi-theater strategy despite material constraints will result in overstretch and neglect the pacing challenge China poses. This concern is not entirely without merit, particularly absent increased defense resources and more disciplined development and employment of the force.

That said, a one-war military is a problem to be solved, not a solution to be embraced.² A one-war military presumes certainty in a security environment in which uncertainty abounds. As the 1997 Quadrennial Defense Review observed,

We can never know with certainty when or where the next major theater war will occur, who our next adversary will be, how an enemy will fight, who will join us in a coalition, or precisely what demands will be placed on U.S. forces. Indeed, history has repeatedly shown that we are often unable to predict such matters.³

A one-war military reduces the commander in chief to a gambler, “turning every decision to use military force into a catastrophically risky ‘all or nothing’ bet.”⁴ As one defense strategist once said, “A force that can only wage one conflict is effectively a zero-conflict force since employing it would require the president to preclude any other meaningful global engagement.”⁵ That’s why DOD never had a one-war planning construct for the Soviet Union during the Cold War.⁶

Even the 2018 and 2022 National Defense Strategies (NDSs) were not meant to be strictly one-war constructs. Both strategies aimed to deter opportunistic aggression while fighting a major war, though they were unspecific as to what forces would be required to do so. As Jim Mitre wrote of the 2018 NDS force-planning construct,

U.S. forces must be able to succeed across a broader range of scenarios and conditions reflecting the breadth and sophistication of adversary abilities. To say that the NDS prioritizes force planning for war against a potential great power adversary does not remove the necessity to deter an opportunistic aggressor.⁷

He went on to say that “force sufficiency for narrowly prescribed scenarios can no longer be the DOD’s primary metric for decision.”⁸

Though DOD can and should prioritize China, building toward a multi-theater military is a hedge against uncertainty. Force planners must do their best to estimate the scale, scope, and duration of a conflict with China. However, should those calculations be wrong, force structure originally fielded for other theaters or a second conflict could be applied as a reserve.

Another set of alternatives would still have DOD commit to deterring or winning a second war but through means other than standing conventional forces: nuclear escalation, wartime mobilization, and burden sharing.

DOD could rely more on its nuclear arsenal to deter opportunistic aggression in a second theater, a modern version of the Eisenhower-era policy of massive retaliation. Such a radical shift in DOD’s approach to warfighting is neither likely nor tenable. US adversaries, especially nuclear-armed adversaries like China and Russia, are likely to doubt the credibility of threats of nuclear escalation in response to conventional aggression against a US ally or partner (e.g., Israel, NATO, or Taiwan). Indeed, many US allies and partners would oppose such a policy.

The United States should remain focused on maintaining strategic deterrence against its two nuclear peers in Russia and China and modernizing its arsenal of strategic and theater nuclear weapons to achieve this objective. That’s why the Congressional Commission on the Strategic Posture of the United States recommended that DOD field sufficient conventional forces to win simultaneous conflicts and avoid increased reliance on nuclear weapons.⁹

Rather than build standing conventional forces capable of fighting two conflicts, DOD could rely on wartime mobilization to rapidly surge manpower and industrial capacity to win a second conflict. This, too, would be problematic. Put simply, it’s already evident that the United States must undertake a massive revitalization of its defense industrial base to build standing conventional forces sufficient for credible deterrence and support US allies and partners. Surge production capacity in excess of present DOD and international demand, especially for major capital systems, is unlikely to materialize in the foreseeable future. Moreover, DOD faces persistent challenges with recruitment and retention. Any significant expansion of end strength in wartime would likely require a compulsory draft, which is a heavy burden on the national leadership’s political will.

Given current industrial and personnel limitations, the best-case scenario is that the joint force replaces personnel and matériel losses during a conflict of limited duration. Force planners should not rely on wartime mobilization to significantly and rapidly produce new force structure sufficient for a second conflict.

Another often-posed alternative to a multi-theater military is to rely more on US allies and partners and entrust them with the primary responsibility for security in theaters such as Europe and the Middle East.

Greater contributions from US allies and partners are not just welcome or fair. Given the scope and scale of the challenges our adversaries pose in Europe, the Indo-Pacific, and the Middle East, such contributions are a necessary complement to a US multi-theater military. Therefore, the question is not whether the United States should ask more of its allies and partners. It should. Rather, the question is how best to ensure that greater contributions from allies and partners actually materialize and do so in a manner that supports US strategic interests; aligns with US force design, development, and employment priorities; and enhances the credibility of deterrence against shared adversaries.

While a comprehensive answer to this question is beyond the scope of this chapter, there are some key observations salient for a US multi-theater military.

Greater allied and partner contributions will not remove the need for US leadership. US interests in theaters like Europe and the Middle East are too important to simply delegate and hope things turn out for the best. The United States and its frontline allies are not better off outsourcing Russia policy to France or Germany or likewise entrusting Iran policy to Saudi Arabia or the United Arab Emirates. That’s why the United States should seek to preserve its political and military leadership of (formal and informal) coalitions to deter and defend against Russia and Iran—leadership that is underwritten by a sustained (though perhaps reduced) US military commitment in each theater.

Greater allied and partner contributions will not materialize quickly or alleviate the demand for US forces in key theaters. Just as in the United States, allied and partner investments in expanding force structure and rejuvenating the defense industrial base will take many years to show results. Indeed, many allies and partners are starting from a weaker position than the US. US force planners should not make assumptions about any significant increase in allied and partner capability or capacity in the near to medium term.

Achieving greater allied and partner contributions will require resolute US leadership, deft US diplomacy, and uncharacteristic US patience. And the US must find ways of holding nations accountable for meeting their commitments. That said, political threats, acts of retribution, and the sudden withdrawal of US troops from allied nations risk political backlash, splintered alliances, or—worse—driving friendly nations into making accommodations with US adversaries.

Europe and South Korea are the most likely places where the US could gradually reduce its overall military commitment while remaining confident in the political strength of each alliance and the long-term trajectory of allied capability and credible deterrence. NATO allies can take, should take, and are taking on a larger role in providing for their own defense. Going forward, capability targets apportioned to European allies through the NATO defense planning process should be intentionally selected to reduce overreliance on the United States for key capabilities enablers, as recommended by the Commission on the National Defense Strategy.¹⁰ New European defense investments spurred by Russia’s invasion of Ukraine should focus on delivering on those capability targets. Likewise, South Korea’s military has the will and capability to lead deterrence and defense against North Korea. Its impressive industrial base will continue to bolster its military modernization.

Finally, not all burden-sharing contributions are measured in defense spending as a percentage of GDP. The United States needs more from its allies and partners than bigger budgets. It needs expanded posture access in the Indo-Pacific. It needs partners in Africa, Latin America, and the Middle East to reject Chinese and Russian military presence. It needs allies like Australia, Japan, and the Philippines to agree to arrangements for combined contingency planning and command and control. And it needs allies and partners to overcome parochial political opposition to expanded defense industrial cooperation. All these are critical for a multi-theater military but don’t necessarily come with a price tag.

A New Force-Planning Construct

Determining what a multi-theater military would look like starts with a force-planning construct. It is policymakers’ answer to the question, “What do you want the US military to be able to do?” With a set of fundamental missions, scenarios, and specified time frames, a force-planning construct guides defense planners and budgeteers on the size and shape of the military they should build and the budget required to do so. In this respect, a force-planning construct is a normative statement about the military we should have in the future rather than a strictly objective statement about the military we have at present.

The most recent National Defense Strategy, published in 2022, did not provide a force-planning construct for a multi-theater military. Recognizing increasing global challenges but opposed to increased defense spending, the Biden administration sought to achieve ambitious strategic ends with little to no change in the means (force structure, budget, etc.). To bridge this ends-means gap, the Biden administration sought to change the “ways” of US defense strategy with the concept of “integrated deterrence.”¹¹ This strategy produced a force-planning construct that sized and shaped the force to prevail in one conflict while deterring opportunistic aggression elsewhere with few compelling specifics as to how that would be accomplished. It seemed more like an estimate of what the current force could do than a statement of what the future force must do. In short, the Biden administration adopted—rather than adapted to—the limitations of the joint force.

Going forward, the next National Defense Strategy, due in 2026, should articulate a force-planning construct for a multi-theater military with certain key attributes.

A force-planning construct must be selective, prioritized, and resource informed. As the Commission on the National Defense Strategy stated, DOD force planning “must be prioritized to effectively and efficiently allocate finite resources, address threats of varying scope and scale, and ensure a mix of US instruments of national power that are tailored to specific strategic objectives.”¹² Even with a multi-theater military, the United States cannot defend every one of its interests with equal vigor simultaneously. Overly ambitious force-planning constructs along these lines “have typically led to force structure estimates twice as large as more-realistic, budget-informed planning approaches.”¹³

A corollary proposition is that force-planning constructs must be based on not only plausible scenarios but military responses that are feasible within reasonable political and financial constraints. The Kennedy and Johnson administrations based their “2 ½ war” construct on a scenario involving a conflict with the Soviet Union in Europe, a war in Asia, and a potential “brushfire” in the Western Hemisphere.¹⁴ While rooted in plausible scenarios during this tense period of the Cold War, this force-planning construct proved unaffordable and impossible, especially given the costs of the Vietnam War. Consequently, it ceased to meaningfully influence the direction of force development.

A new force-planning construct must carefully distinguish among adversaries and conflicts. Force-planning shorthand can often confuse more than it clarifies. The post–Cold War “two-war” planning construct referred to two “major regional contingencies” of similar scale against similar adversaries (e.g., Iraq and North Korea) engaged in similar forms of aggression (e.g., an “armor-heavy, combined-arms offensive against the outnumbered forces of a neighboring state”) requiring a similar US response (e.g., rapidly deploying forces into the region, halting the invasion, and defeating the aggressor).¹⁵ A force-planning construct for a multi-theater military would not be a return to two-war construct for the simple reason that there are no two wars the United States might fight against its potential adversaries that are likely to be of similar scope, scale, intensity, and duration. A war with China is not the same as a NATO-Russia war. Neither of those is the same as an operation to take out Iran’s nuclear program. Simply labeling all three as “wars” misses the point.

Finally, a new force-planning construct must make realistic assumptions about international force contributions accounting for differences in the nature of US alliances and partnerships in key theaters. Consider the contrast between US alliances in Europe and the Indo-Pacific. In Europe, the United States enjoys a highly institutionalized, multilateral alliance committed to coalition warfare and deeply ingrained in DOD’s doctrine, organization, training, matériel, leadership and education, personnel, and facilities (DOTMLPF). NATO engages in detailed planning for collective defense, including preassigning forces to specific plans to be maintained at high readiness and made available to the alliance on an assured basis.¹⁶ In the Indo-Pacific, the United States has a hub-and-spoke network of bilateral alliances of varying degrees of maturity. In a conflict with China involving a Taiwan scenario, allied contributions are not guaranteed, let alone specified in advance. Thus, DOD force planners should make conservative and differentiated assumptions about the contributions of allies and partners.

With these factors in mind, DOD should adopt a force-planning construct that sizes and shapes the joint force to simultaneously do the following:

• Defend the homeland;
• Maintain strategic deterrence;
• Deter and, if necessary, defeat Chinese aggression in the Indo-Pacific in a major, potentially protracted conflict;
• Deter and, if necessary, defeat Russian aggression against the NATO alliance as part of a US-led but predominantly European combined force; and
• Conduct targeted military operations in the Middle East, including with regional partners, to counter and dissuade Iranian malign activities and prevent mass-casualty terrorist attacks.

To be clear, the US military is not currently sized and shaped for such a force-planning construct. Over the long term, defense budgets should be designed to build a force capable of defending against an axis of aggressors on multiple fronts. Until we can build that force, prioritization in force design, development, and employment will be critical. In each of these areas, China should remain the highest priority.

Changes to Contingency Planning

A new force-planning construct must be complemented by changes in DOD contingency planning to effectively shape the department’s strategic direction. DOD contingency plans shape not only the employment of the current force but also the design and development of the future force. The secretary of defense’s Defense Planning Guidance, Contingency Planning Guidance, and specific campaign and contingency plans are key inputs into joint and service concept development and requirements-generation processes.

Congress assigned the role of global integrator to the chairman of the Joint Chiefs of Staff in the National Defense Authorization Act for Fiscal Year 2017.¹⁷ Since then, DOD has increased focus on the conduct of integrated contingency planning across combatant command areas of responsibility, functions, and domains and on managing the reallocation or reassignment of forces globally. For example, DOD has made progress in ensuring that operation plans are developed with realistic assumptions about the availability of forces in functional areas such as transportation, the cyber domain, space, strategic deterrence, and homeland defense.¹⁸

However, despite these improvements, DOD’s contingency planning is not optimized for a multi-theater military. Going forward, DOD contingency planning must account for multiple simultaneous conflicts, the possibility of protracted conflict, and the defense industrial base support required for successful execution of the conflicts.

Generally speaking, DOD does not plan for simultaneous contingencies. Instead, it develops “integrated contingency plans” that coordinate “the activities of multiple [combatant commands] in time and space to respond to a single contingency” (emphasis added) across geographic boundaries and functional responsibilities.¹⁹ Consequently, any two contingency plans executed simultaneously would risk making overlapping or conflicting claims on the same forces, functional support, and resources. Contingency plans involving combat operations at significant scale would be at the highest risk.

Instead of regular contingency planning, DOD treats “multiple crises” that “concurrently impact two or more” combatant commanders as a situation to be handled by “planning in a crisis,” which often takes place on condensed timelines in direct response to events.²⁰ DOD regularly conducts crisis planning, refining or adapting existing plans into executable operation orders or developing them from scratch in unforeseen circumstances.

Multiple simultaneous conflicts would not be an out-of-the-blue scenario, and planning for this should not be deferred to crisis planning. Such a scenario is all too plausible and its consequences for national security too grave to be planned on the verge or in the midst of calamity. Planning for simultaneous conflicts in multiple theaters should be part of DOD’s regular contingency planning.

Likewise, DOD contingency planning does not sufficiently account for the possibility of a protracted conflict. Since the end of the Cold War, DOD has generally assumed “that technology-fuelled advances in combat velocity will automatically lead to great-power wars that are shorter, sharper, and more localised.”²¹ This assumption is no longer valid. Great-power adversaries will not necessarily terminate their aggression due to an initial failure to achieve their objectives rapidly. Indeed, as Russia has done in Ukraine, an adversary may persist in its aggression, calculating that it can outlast the political will and material capacity of the United States and its allies and partners. Indeed, experts warn that a conflict with China “could morph into . . . a protracted struggle that also evolves into a gruelling war of attrition, spanning multiple theatres and drawing on all dimensions of national power.”²²

Furthermore, bureaucratic incentives tend to bias DOD toward planning for shorter wars. As Evan Montgomery and Julian Ouellet assess, “Planning scenarios used for strategy are often simultaneously used for constraining service budgets—all else being equal, shorter wars should be cheaper than longer wars.” Shorter wars are also easier to plan, focusing on “quantifiable and easy-to-measure issues such as force flows, exchange ratios, and attrition rates” rather than “qualitative and hard-to-measure[] topics such as adversary will and resolve,” on which longer wars may turn.²³

Planning for protraction is essential not just because such a scenario is plausible. Short and long wars are fundamentally different—even opposite—in their theory of victory, concepts of operations, and time-phased force requirements. Moreover, failing to account for protraction in a conflict in one theater may render the joint force unable to respond to crisis or conflict in another theater.

DOD contingency planning also needs better integration with defense industrial planning. The Commission on the National Defense Strategy observed that DOD contingency plans do not sufficiently consider needs specific to the industrial base relevant to the execution of operational plans, leading to an “operational-industrial gap.”²⁴ DOD should incorporate the defense industrial base directly into its contingency plans, specifically issues such as war reserve matériel requirements, prioritized wartime surge production needs, anticipated Defense Production Act (DPA) Title I actions in wartime, and alignment of DPA Title III actions with contingency plan requirements.

Fortunately, Congress has recognized the need to update DOD contingency planning practices and processes. In section 1074 of the Servicemember Quality of Life Improvement and National Defense Authorization Act for Fiscal Year 2025, Congress instructed DOD to assess and report on its operational plans, specifically its planning assumptions for simultaneous and protracted conflicts. This is a welcome intervention of congressional oversight.²⁵

The next secretary of defense should go further and issue contingency planning guidance to account for multiple simultaneous conflicts, protracted conflict, and the defense industrial support required for successful execution. At a minimum, the secretary should direct the development of contingency plans detailing how the joint force would respond to Russian or Iranian aggression when already engaged in an all-domain conflict with China.

DOD may assess plans developed for simultaneous or protracted conflict to be impossible to execute given limitations on the forces assumed or projected to be available. Likewise, execution risk might result from defense industrial base limitations. But that is exactly why this detailed planning and analysis must take place now: to give DOD and congressional leaders an authoritative account of the capability and capacity gaps that must be addressed for the United States to build a multi-theater military.

Concept Development and Force Design

With the 2018 National Defense Strategy, DOD acknowledged that assumptions underpinning the traditional “American way of war” no longer hold. DOD cannot count on an expeditionary force projection model in which the joint force can use uncontested logistics to deploy large numbers of forces thousands of miles from its homeland sanctuary to largely invulnerable bases near the theater of operations, build up over a lengthy period, and then commence offensive operations at a time of its choosing with ample intelligence support and the overwhelming technical advantage to establish all-domain superiority and degrade enemy forces such that US forces can achieve operational objectives with minimal casualties.²⁶ DOD recognized it needed a new model for operating a multi-theater military. And it’s been searching for one ever since.

Over the past several years, the Joint Staff and the services have developed a variety of new warfighting concepts and pursued new force design initiatives to address threats from advanced adversaries like China and Russia. These include the Joint Warfighting Concept, the Army’s multi-domain operations, the Air Force’s Future Operating Concept, the Marine Corps’s Force Design 2030 and suite of supporting concepts, and the Navy’s Navigation Plan and Distributed Maritime Operations concept. To varying degrees, these efforts have focused on similar force attributes and capabilities: integrated command and control; dispersal, distribution, and expanded maneuver; resilient logistics; long-range fires; persistent ISR; force protection; and air and missile defense.

However, major questions remain as to how DOD intends to assemble this hodgepodge of concepts and force designs into a coherent joint concept with a feasible theory of victory. Moreover, with the exception of the Marine Corps, these force design and concept development efforts have had a limited impact on the joint force’s overall trajectory.

The Navy and Air Force in particular seem unable to achieve internal consensus sufficient to initiate and sustain decisive changes in force design and future force structure. Both services are mired in interminable debates on interrelated questions about the proper mix of near-, medium-, and long-term investments; manned and unmanned systems; survivable and attritable platforms; stand-in and standoff forces; service-retained forces in the continental United States; forward-stationed assigned forces; and more. Critical decisions and the concepts and force design necessary to move the joint force toward a multi-theater military are being deferred, with risk-averse service leaders unable or unwilling to resolve these issues.

For the two most capital-intensive services, the longer these debates rage on, the slower or more expensive their options become, if they don’t disappear entirely. The lack of sufficient, timely, and predictable defense budgets makes this problem worse. Budget uncertainty prolongs debate and instills pessimism that renders creative, bold solutions as unaffordable luxuries. This strategic paralysis leaves both services trapped in a death spiral: perpetually shrinking, divesting force structure due to budget constraints despite unyielding operational tempo, and investing more dollars in smaller numbers of exquisite platforms that are slow to arrive (if they ever do).

Meanwhile, the Army appears to have a relatively stable force design and conceptual approach. The real question is whether the Army is big enough to fulfill its own vision. Dwindling end strength is harming Army readiness and risks leaving the service too small to carry out its broad set of roles and missions. It recently announced the elimination of 32,000 billets to free up space for personnel aligned to key modernization capabilities.²⁷ An ever-shrinking Army will struggle to provide the land power backbone in Europe and South Korea, serve as the “linchpin service” in the Indo-Pacific, and maintain responsibility for joint capabilities already under strain, like integrated air and missile defense.²⁸

The challenges of the Navy, Air Force, and Army to decisively establish and effectively implement consistent force design and warfighting concepts directly impede a multi-theater military. These struggles cut right to the heart of being able to field the right mix of capabilities at sufficient capacity and readiness to operate across multiple theaters.

Decisive political leadership and budget certainty are two critical aspects of the solution. The secretary of defense, deputy secretary of defense, and secretaries and undersecretaries of the service departments must personally drive decision-making processes to definitive conclusions and enforce strict adherence to defense planning and budgetary guidance. We need decision-makers that actually make decisions and stick to them, not risk-averse officeholders who prefer no decision to the wrong decision. Time has run out for that. Meanwhile, Congress must appropriate sufficient, timely, and predictable funding that provides financial space for bold solutions and a sufficient time horizon to carry force design and concept development initiatives to fruition.

When it comes to concepts, the secretary and deputy secretary of defense must push for a true joint operating concept that drives service concept development (rather than the other way around) and directly influences service force design and development priorities.

DOD should place increased emphasis on concepts of denial, particularly for China and Russia. Rather than focusing on how to overcome enemy anti-access and area-denial capabilities to enable US force projection with existing force structure, future concepts should emphasize preventing adversaries from projecting force and defending the territory of allies and partners using asymmetric capabilities. Ukraine’s successful sea-denial campaign against Russia in the Black Sea shows the promise of this concept.²⁹ The US Indo-Pacific Command’s recently announced “hellscape” concept suggests DOD is also beginning to move in this direction.³⁰ These defensively oriented concepts, which do not assume or require superiority or dominance in a particular domain, would also be more easily adopted by allies and partners.

Future concepts also need to more fully consider the long game and the endgame, particularly for China and Russia. As previously mentioned regarding contingency plans, DOD’s operational concepts tend to emphasize conflicts of limited duration. DOD needs to focus more on concepts for protraction. This is less about industrial considerations of what to build in the event of protracted conflict. Rather, it is about how the joint force, in concert with other elements of national power, presses US advantage between major operations. DOD also needs to place greater emphasis on concepts for war termination, particularly in conflicts with China and Russia, nuclear adversaries against whom total victory is unlikely if not impossible.

Closely aligned with concept development, leaders in the Office of the Secretary of Defense and the service should advance force design initiatives that fully embrace broad and deep adoption of autonomous systems, lower-cost weapons, and the software-defined networks and command and control systems that power them. Combatant commands should be given a strengthened hand in influencing force designs to ensure these new technologies are tailored for multi-theater application.

Budgets and Force Development

A multi-theater military requires a variety of capabilities for specific operational challenges. But more fundamentally, it requires additional capacity. A multi-theater military needs affordable mass that demonstrates to adversaries that the joint force can operate flexibly across multiple theaters simultaneously, absorb attrition, and generate sustained combat power in a protracted conflict.

Business as usual will not produce affordable mass. DOD must confront the harsh reality that any strategy that seeks to restore US military superiority “solely by growing today’s munitions stocks and force structure is doomed to fail.”³¹ The atrophy of the defense industrial base and the sclerosis of the acquisition system mean that rapid growth of traditional force structure is no longer possible.

That is why DOD needs to embark on an ambitious and transformative shift of procurement dollars over the near and medium term to scale production of lower-cost, mass-producible, all-domain autonomous systems. The time for decade-long research and development projects and innovation theater is over. The systems should be procured in large quantities and fully integrated into joint and service DOTMLPF to complement existing force structure. Rather than the smaller, tactical, shorter-range systems employed in Ukraine, DOD should focus on establishing programs centered on larger autonomous vehicles that have sufficient range, power, payload, and survivability to be relevant in the geographically expansive, operationally stressing environment of the Indo-Pacific. These systems would also be valuable in projecting power over greater distances in the air and maritime domains against Russia and Iran.

DOD would likely need to procure these capabilities outside the traditional acquisition system to ensure speed and avoid burdensome, industrial-age requirements processes ill-suited to this technology. Likewise, DOD should lean heavily into the commercial sector, which has advanced the foundational technologies behind autonomous systems to build a new, alternative defense industrial base to produce these systems at scale.

At the same time, DOD should prioritize ease of exportability as it develops and fields autonomous systems, forming the basis of a new class of cooperative programs with allies and partners. Autonomous systems could be a new frontier of defense industrial cooperation delivering a diplomatic, military, and economic force multiplier.

A multi-theater military also requires a substantial increase in munitions stockpiling and production. DOD should expand the use of modular kits to turn dumb bombs into precision weapons, as well as glide kits³² and other add-ons that extend the range of existing precision weapons. Most importantly, DOD needs to move beyond efforts to increase the production of existing weapons and accelerate the development and production of new weapons types.

In particular, DOD should prioritize modular weapons that can be more easily manufactured at a lower cost by a wider variety of producers making greater use of commercial supply chains.³³ Rather than focus on piling as many exquisite and expensive capabilities as possible onto one missile, modular weapons would allow DOD to build heterogeneous salvos that would be more survivable and cost-effective. This approach would provide the military services with the acquisition flexibility to buy more modular weapons ahead of need rather than waiting to procure systems that meet a precise operational requirement. Likewise, it would provide operational flexibility for warfighters in multiple theaters to tailor sensors and payloads by the minute in accordance with their needs.

In addition to autonomous systems and lower-cost weapons, other DOD budget and force development priorities should include resilient, all-domain sensing networks; integrated air and missile defense; long-range fires; and contested logistics, including expanding the Combat Logistics Force.

To be clear, the United States can and should make some long-term investments in the traditional defense industrial base, especially shipbuilding. Critical programs such as the Virginia-class submarine must be kept on track to preserve critical US advantages. And programs such as the B-21 bomber should be expanded to ensure long-term capacity in key capability areas. However, these investments alone will be insufficient without focus on the affordable mass delivered by autonomous systems and low-cost weapons.

Posture and Force Employment

One of the fundamental challenges for a multi-theater military is how the joint force is postured and employed during competition and crisis.

Lack of capacity is clearly a major problem, routinely forcing high-demand, low-density assets to be shifted between theaters in response to events largely outside US control. DOD cannot operate a multi-theater military if global force management is reduced to a game of Whac-a-Mole across three theaters.

Most obviously, it harms military readiness. The US military is too small to handle unexpected deployments of any sustained duration. The counter-ISIS campaign caused a “readiness crisis” and depleted munitions inventories.³⁴ Immediately following defense budget increases to repair readiness, the “maximum pressure” campaign against Iran wore out the US Navy and led to consecutive record-long aircraft carrier deployments.³⁵

Furthermore, an approach of robbing Peter to pay Paul produces a toxic boom-bust cycle in global force management in which forces are taken from one theater (raising questions about US commitment), sent to another theater (raising expectations about US commitment), eventually withdrawn (leading to disappointment), and finally returned to the theater from which they came (where their impermanence undermines their deterrent value).

But a lack of capacity is not the only issue that must be addressed to operate a multi-theater military. DOD needs to take a deeper look at the relationship between global force management and deterrence, particularly the rationale behind shifting allocated forces between theaters.

Broadly speaking, the United States has accustomed itself, its allies and partners, and its adversaries to a language of deterrence in which the deployment of forces into a given theater is the vocabulary of choice. While force deployments can send a powerful deterrent message, overreliance on them is problematic.

First, there is the obvious capacity issue. When there are too few forces to go around, force deployments tax military readiness and increase risk in other theaters. Second, there is the risk that policymakers become less intentional and discerning in their decisions to deploy forces and instead treat such deployments as a knee-jerk response to any international tension. Likewise, a third risk is that force deployments become too focused on activity rather than outcomes. Policymakers may come to value the political message that force deployments send at home, for example, rather than the actual effect they have on adversaries’ behavior. Fourth, frequent force deployments increase the risk that adversaries view any reduction in operational tempo as a signal of reduced US commitment.

Rather than attempting to dynamically shift forces between theaters, DOD should aim to build a multi-theater military composed of more capable, self-sufficient assigned forces stationed forward in key theaters. The aim should be to enable combatant commanders to more sustainably manage competition and crisis and respond more rapidly and effectively in conflict.

In this model, combatant commanders would have greater resources and accountability for managing their assigned missions with their assigned forces, including in periods of increased tension. Reducing their reliance on additional allocated forces, combatant commanders would make greater use of a broader portfolio of flexible deterrence options. Alternative actions might include increasing the readiness posture of forces already in theater, upgrading alert status, conducting show-of-force actions, increasing and expanding ISR collection, conducting increased or short-notice training and exercise activities, and increasing active and passive protection measures.

Greater emphasis on forward-stationed assigned forces would have other benefits as well. Enduring command relationships with a combatant command would enable service-provided units to build deeper theater-specific expertise and relationships, increase readiness for specific contingencies through focused planning, and expand participation in joint planning and training. More assigned forces might also narrow the gap between the needs of warfighters in the combatant commands and the planning and budget of the services responsible for manning, training, and equipping the force. Units would be in a better position to advise their services on theater-specific requirements. Meanwhile, assigned forces would provide combatant commanders a longer planning horizon than allocated forces and increase their insight and influence in the planning, programming, budgeting, and execution process.

Increased assigned forces would also enable combatant commanders to respond more rapidly and effectively to adversarial aggression. China and Russia in particular may seek to use speed and local geographic advantages to rapidly achieve military objectives before the United States can mount an effective response and to use the threat of further escalation to coerce war termination on favorable terms. To defeat this theory of victory, forward-stationed assigned forces would be sized and shaped to deny early adversarial gains with minimal early warning and without major reinforcements, buying time for a larger-scale US response. These forces would be first in line to receive asymmetric capabilities such as lethal and attritable autonomous systems. They would require increased forward stocks of munitions and fuel. And they would need more capability to survive and operate in the face of sustained attack through emphasis on mobility, hardening, dispersal, deception, and active and passive defenses.

The Indo-Pacific should be the first priority for posture improvements and additional assigned forces. DOD continues to move slowly to realize the more capable, distributed, and resilient posture it professes as its goal. As Zack Cooper lays out in his chapter, the United States will have to pursue multiple lines of effort simultaneously. These include vigorous defense diplomacy to expand US access to more operating locations. To the greatest extent possible, the United States should press to expand combined basing with allies like Australia, Japan, and the Philippines to complicate China’s strategic and operational calculus. DOD will have to field more systems capable of operating from austere locations with minimal infrastructure support, including mobile missile launchers, autonomous aircraft, and unmanned surface and undersea vessels. At the same time, DOD will have to continue investing in long-range projection platforms as a complement to its forces operating forward.

As it continues to allow more resource-efficient approaches in other theaters, DOD should consider managing forces in Europe and the Middle East more closely together. Over many years of instability and conflict, the United States has routinely moved ground, air, and naval forces on rapid timelines from Europe to the Middle East to defend its interests there.³⁶ Building on this, DOD should consider building the eastern Mediterranean into a strategic hub to defend US interests in Europe and the Middle East. This would entail increasing US force presence in countries like Greece and Romania. At the same time, overall assigned forces in the Middle East would decline even as DOD maintained a constellation of small distributed bases in the region. In this way, the US could reinforce NATO’s eastern and southern flanks, retain forces close to the Middle East for crisis and contingency response, and improve US capability and capacity for the defense of Israel.

Conclusion

More than any specific policy recommendation made in this chapter, the most important resource for building a multi-theater military is political will. This moment of crisis and decision requires active political leadership from the president, the secretary of defense, and senior DOD officials. Building a multi-theater military will pose organizational, conceptual, technical, and financial conundrums. But none of these are beyond the United States’ ability to solve. Fundamentally, we face a test of statesmanship, and the stakes could not be higher. We must not squander what opportunity remains to fundamentally change the course of US defense policy in time to prevent a war rather than fight one.

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