By Tyler Hacker

The following article is adapted from a new report by Tyler Hacker at the Center for Strategic and Budgetary Assessments (CSBA), Arsenal of Democracy: Myth or Model? Lessons for 21^st-Century Industrial Mobilization Planning.

As conflicts from Europe to the Middle East draw on U.S. munition stocks, many of which are already insufficient for great power conflict, leaders are calling on the U.S. military and defense industrial base to rapidly increase munitions production. In doing so, many reference the United States’ industrial mobilization during World War II, which transformed the nation into the indispensable “arsenal of democracy” and greatly contributed to Allied victory.

A protracted war between the United States and China would demand immense quantities of munitions and would require the industrial base to grow to meet these demands. This is industrial mobilization, a topic the nation has not seriously considered since the end of the Cold War. Given this lapse in focus, it is only natural to look to the nation’s last major mobilization for great power war, World War II, as a model for the future.

But World War II was over eighty years ago, and much has changed since the nation set out to expand war production to eventually supply two thirds of all weapons used by the Allied nations. What can contemporary policymakers learn about industrial mobilization from the arsenal of democracy?

Interwar Mobilization Planning and Its Continued Relevance

Examining the history of World War II industrial mobilization begins in the interwar period, a time when the U.S. military spent nearly two decades planning for industrial mobilization. The nation’s chaotic mobilization for World War I in 1917—an effort which proved too late to equip doughboys sent to Europe—spurred Army planners to develop a series of procurement and mobilization plans and actively engage with the nation’s industrial base during the 1920s and 30s. Although President Franklin Roosevelt did not implement these plans in their entirety when he began readying the nation for war in the late 1930s, many of the plans’ elements and the preparations they spurred left the nation in a much better position relative to 1917.

Although interwar mobilization plans proved integral to building the arsenal of democracy, America’s wartime industrial achievements were ultimately made possible by the circumstances of the era: a homeland sanctuary that provided the U.S. military several years to mobilize the world’s most powerful economy and manufacturing base toward war production. The United States confronts a drastically different set of strategic, economic, and industrial conditions today. Recent efforts to increase production of critical munitions have resulted in modest gains over several years and confronted numerous bottlenecks, revealing the inadequacy of America’s post-Cold War industrial base.

Nevertheless, the nation’s mobilization for World War II and interwar planning efforts hold many enduring lessons for contemporary policymakers as they consider industrial expansion in the modern era. The details of mobilization such as the military hardware that must be produced, essential industrial sectors, and critical materials and their sources may be very different today, but the enduring relationship between strategy and logistics, as well as the interactions between the U.S. government, the military services, and the industrial base, remain the same in many ways.

If a war between the United States and China requires increased production of military hardware, then the history of World War II’s mobilization contains numerous insights into the fundamental planning considerations, tradeoffs, and risks inherent to industrial mobilization in the United States. Moreover, the period provides an opportunity to examine how prewar preparations and plans played out once mobilization began and how industrial output progressed alongside military demands and expenditures in campaigns from 1942 to 1945.

Other periods, such as the Cold War, may also hold relevant lessons on mobilization planning, but World War II remains a valuable case study and a significant touchpoint for American leaders and the public alike. These factors invite a reexamination of the period with an eye toward applying its lessons to today’s strategic environment and industrial base. This analysis highlights five lessons for today’s military planners as they consider industrial mobilization in the 21^st century.

Lesson One: Establishing Requirements is Central to Mobilization Planning

A recurring theme in interwar mobilization planning is the central importance of determining military requirements for protracted war. Before mobilization can begin, the military must determine the types and quantities of materiel it requires to execute its strategy and, in turn, that industry must produce. Throughout World War II, these requirements were intimately linked to allied strategy, with changes in either often dictating modifications to the other.

President Roosevelt set expansive production goals in his December 1940 “arsenal of democracy” fireside chat, but the details of exactly which guns, planes, and ships to produce were left unanswered. Industrial expansion could not be completed until the military services developed firm, specific requirements. Amid these efforts, the president requested an assessment of “over-all production requirements” in August 1941, which tasked the military with estimating the total number of men it would put in uniform, how these men would be organized into fighting units, what equipment these units would field, and the rates at which they would expend consumable goods like ammunition and fuel. With this information, civilian mobilization agencies could coordinate production and material requirements into a scheme that became known as the Victory Program. Even so, the feasibility of fulfilling these requirements was hotly debated and ultimately forced the Army to modify its strategic approach, reduced its planned end strength, and modify the composition of fielded forces.

Determining military requirements remains an essential aspect of planning for protracted war and industrial mobilization. The Department of Defense must think deeply about what it might require over the duration of a conflict, from its initial troop basis to replacing hardware and materiel lost to attrition. These requirements should look past current budgetary constraints to consider potential national objectives, strategy, and limitations in a conflict requiring mobilization. The misestimations of interwar plans, such as outdated munition consumption rates, show the enduring challenge of gauging the demands of future war. Requirements must remain flexible enough to account for uncertainties surrounding a war’s specific aims, geography, and methods.

Still, some assessment of requirements remains a prerequisite to industrial mobilization planning and the implementation of effective industrial preparedness measures. Developing such requirements remains entirely within the purview of the Department of Defense. Interwar planners mistakenly assumed that production would rapidly adjust to strategic plans. Today’s Pentagon planners must not repeat this mistake and should begin assessing the military’s needs for a protracted war in order to drive industrial planning.

Lesson Two: Allies Must Be Factored into Mobilization Plans

In developing requirements, the Department should consider the potential needs and contributions of U.S. allies and partners. Throughout World War II, assessing and coordinating allied requirements was a consistent challenge and encouraged Roosevelt to establish civilian mobilization agencies such as the Office of Production Management. The president’s August 1941 request for total production requirements was driven by the German invasion of the Soviet Union and the addition of yet another nation to the list of allies supported via the Lend Lease program. Despite the reliance of U.S. forces on allied equipment during World War I, interwar mobilization plans did not adequately factor in allies. As a result, President Roosevelt’s drive to supply Great Britain, the Soviet Union, China, and other partners around the world threatened to seriously disrupt the military’s own procurement and mobilization plans.

Today, America’s multitude of allies and partners are often touted as one of the nation’s competitive advantages vis-à-vis China. Accordingly, contemporary mobilization plans must consider the materiel these nations might request, as well as their capacity to support industrial expansion. As recent events in Ukraine and Israel have shown, many partners in a U.S. coalition will draw on U.S. production of munitions and platforms. Policymakers are already facing the same dilemma Roosevelt faced in 1941: balancing the support of allies engaged in active conflict with U.S. military readiness. Contemporary mobilization plans must coordinate and deconflict U.S. and allied demands in order to provide the defense industrial base the combined demand signal necessary to expand production capacity.

In today’s globalized economy, U.S. allies may also play a larger role in defense supply chains. World War II mobilization officials were forced to balance limited domestic sources of critical materials with the transportation requirements and transit time inherent in foreign sources—a tradeoff that often led them to expand domestic capacity or establish domestic substitutes, such as synthetic rubber. Similarly, today’s military-industrial plans must fully consider the benefits and risks of relying on allies and partners in defense supply chains. An industrial coalition of the United States and its close allies in Europe and Asia is a formidable opponent to China’s massive industrial base, but military planners must understand how relying on foreign sources might impact production timelines and create vulnerable supply lines throughout the world. Effectively leveraging allied industrial capacity also calls for a rebuilding of the U.S. Merchant Marine to ensure the United States maintains the ability to keep manufacturing inputs flowing from its overseas allies and partners.

Lesson Three: Mobilization Plans Cannot Ignore Threats to the U.S. Homeland

World War II’s mobilization benefited from the relative invulnerability of the continental United States, which provided sanctuary for an extended industrial buildup before the nation committed its forces to large overseas campaigns. Even in this relative safety, military and industrial planners worried about the vulnerability of production facilities on the nation’s coasts and focused new plant construction in the American heartland. To mitigate the threat of sabotage, the government distributed war production over a broad geographic area and built redundant facilities to reduce the number of bottlenecks and single points of failure.

Today’s potential adversaries possess numerous capabilities to disrupt or destroy U.S. defense production and critical infrastructure, from kinetic strikes to sabotage and cyberattacks. Indeed, Russia is already utilizing unconventional warfare to disrupt Western defense production in support of Ukraine. The destruction of the Nord Stream 2 pipeline and recent cutting of undersea cables foreshadow the sorts of asymmetric infrastructure attacks that could be employed to impede war production before or during a conflict.

Defending the industrial base will require numerous lines of effort across multiple domains. Within industry, additional force protection measures may be necessary to prevent physical sabotage alongside cyber and network defenses. Domestic air and missile defenses, such as those proposed in the Department’s Golden Dome project, may be necessary around critical industrial and logistical nodes. Of course, planners must consider how these requirements will draw on limited resources and low-density assets. All in all, the vulnerability of the U.S. defense industrial base calls for a renewed focus on homeland defense, the U.S. Northern Command, and various civil defense organizations. The Pentagon must work with its industrial partners to reduce vulnerabilities, disperse critical functions, and harden weak points in defense production facilities.

Lesson Four: Mobilization May Influence the Design of Military Hardware and U.S. Military Force Structure

Protracted war and industrial mobilization will shape the design of individual weapons in the American arsenal and have implications for the U.S. military’s broader force structure. Industrial and material limitations often forced the military to accept modified weapon designs during World War II’s mobilization. Many weapons developed in arsenals during the interwar period were complex and failed to leverage the latest mass production techniques of the period. The demands of mobilization pushed industrialists to modify designs to simplify production, increase efficiency, and maximize output. Military officials were often skeptical of these changes despite their centrality to achieving output objectives.

Likewise, today’s exquisite weapons may need to be modified to increase their manufacturability, and the military should consider reevaluating minimum performance requirements to assess the potential for material substitutions and process modernizations in weapon manufacturing. If today’s suite of military hardware proves unsuitable for scaled production, then entirely new classes of weapons must be designed with mobilization and producibility considered alongside other performance requirements.

These changes and the evolving demands of protracted war also have two significant implications for U.S. military force structure. First, the standing military must be capable of fighting until industry is mobilized to replace losses and support the campaigns required for victory. Planners should consider how attrition and materiel shortages will affect strategic requirements and concepts of operation. The force must be capable of adapting to unforeseen circumstances, new missions, and the losses that are typical in great power conflict.

Second, industrial planning must foster a production base flexible enough to design and produce new weapons in addition to existing systems. World War II saw the adoption of novel technologies and fleets of new aircraft, naval vessels, and ground vehicles. Industrialists could not settle for mass producing existing, proven designs, but instead had to produce systems under constant modification in response to battlefield feedback and evolving missions and requirements.

Lesson Five: Mobilization is a Competitive Activity

Finally, World War II shows how mobilizing a nation’s military-industrial complex for war is inherently a competitive endeavor in which both belligerents attempt to bring their national resources to bear and provide their forces with the firepower necessary to outmatch their opponent and accomplish military and political objectives. The arsenal of democracy was paired with political and military campaigns to degrade the production capacity and supply lines of the Axis powers, from diplomatic efforts to secure foreign sources of raw materials to strategic bombing against German aircraft production facilities.

Any future conflict requiring industrial mobilization could be accompanied by similar campaigns and efforts. The Department of Defense should consider how it might disrupt enemy supply chains, transportation networks, and military-industrial facilities via non-kinetic and kinetic means. Military planners should assess the value of industrial and economic targets and the forces and weapons optimal for attacking these targets, which may be different than those optimized for destroying military forces. In any case, imposing costs and impeding adversary war production should be a vital part of any military-industrial strategy for protracted great power war.

Applying the Lessons of World War II

As the U.S. military prepares to deter and, if necessary, fight a war with China, industrial mobilization planning and industrial preparedness take on a renewed significance not seen since at least the end of the Cold War. Chinese concepts such as military-civil fusion show how seriously America’s adversaries consider mobilization and the importance of industrial capacity in future warfare. In the nuclear age, mobilization planning and a healthy defense industrial base should be viewed as not only important for prevailing in great power war, but also as key elements in deterring such an outcome. The dangers of failing to prepare the U.S. industrial base for protracted war are grave, from leaving U.S. forces with empty magazines to pushing decision makers to abandon treaty commitments or over rely on nuclear threats.

Developing industrial mobilization plans and implementing long-term measures to strengthen the industrial base risk being discounted by military officials as overwhelming or unachievable tasks due to their scale, complexity, and the need to coordinate across government agencies and the private sector. But the Pentagon must start somewhere, and the interwar period and World War II hold valuable lessons as planners address this challenge. Many aspects of mobilization planning and aligning strategic ends with industrial means remain unchanged, and the U.S. military should look to this era for both instruction and inspiration. If interwar mobilization plans prove anything, it is that no plans will ever be perfect. But as Dwight Eisenhower, himself a key author of the 1930 industrial mobilization plan, noted: “Plans are worthless, but planning is everything.”

Tyler Hacker is a fellow at the Center for Strategic and Budgetary Assessments (CSBA), where his work focuses on long-range strike, the defense industrial base, and operational concepts for great power conflict.

Featured Image: The factory floor of a F-35 production facility in Fort Worth, Texas. (Lockheed Martin photo)