The Future of Land Warfare

Front matter

MICHAEL E. O'HANLON

THE

FUTURE

Contents

Preface 1 Introduction: Historical, Strategic, and Technological Context 2 Conflicts Real, Latent, and Imaginable Scenarios with Russia or China 4 — Scenarios in South Asia, the Middle East, Africa, and the Americas Toward an Army of the Future for the United States The Case for a Million-Soldier U.S. Army APPENDIXES A Resources and War B Breakdown of the U.S. Army by Function, 2014 C U.S. Army and Marine Corps Personnel by Region and Country, 2014 D Key World Indicators: Competitiveness and Vehicle and Steel Production Notes Index

Xi viii Contents

MAPS

Preface

IN THIS BOOK, I have the pleasure and honor of helping initiate a new Brookings book series linked to the upcoming 2016 presidential race as part of the Foreign Policy program’s Order from Chaos project of 2015-16.

The nation’s next president and Congress, when they begin to govern in2017, will confront issues addressed here, especially defense planning in a time of austerity. The 2011 Budget Control Act remains in effect and, as of this writing, continues to hang like the sword of Damocles, threatening a return to sequestration for all programs funded through federal discretionary spending—the military budget, foreign aid and diplomacy accounts, homeland security funding, and domestic investment in matters ranging from education to infrastructure to scientific research to food and highway and air safety. National security funding will decrease as much as one-third from its annual peak of more than $750 billion (expressed in 2016 dollars) in the late Bush and early Obama years. Of course, that will hardly result in an austere military budget by most perspectives—$500 billion for the Pentagon would still roughly equal the cold war average adjusted for inflation and would exceed China’s budget by roughly a factor of three, while accounting for nearly 40 percent of global military spending. But the projected pace and steepness of funding xi xii Preface declines will nonetheless be severe compared to 2010 (indeed, they will be severe even if sequestration-level cuts are averted).

In this context, some, such as Gary Roughead, former admiral and chief of naval operations, have called for very deep cuts in the U.S. Army—roughly 50 percent, in his case. My analysis can be read as a counter to his proposal and, more generally, to those who would attempt to handle declines in defense spending largely by cutting the nation’s ground forces. My solution is a more measured one, combining various defense reforms with modest real increases in the nation’s annual spending for the base defense budget going forward (anticipating that war costs will continue to decline somewhat).

Viewed in the context of the Order from Chaos project, spearheaded by my friends and colleagues Martin Indyk and Bruce Jones, the book has a slightly different additional purpose. With parts of the world showing signs of anarchy in 2014 and beyond, the questions for the United States become, how do we reduce the chaos in ways compatible with American interests and at a reasonable cost?

The world writ large, however, is not necessarily chaotic at this juncture of history. Crises from Ukraine, to Iraq and Syria and Yemen and Libya, to Liberia and Sierra Leone and Nigeria have created a sense of deep unease in recent times. Many of the problems will surely endure through the 2016 presidential campaign and beyond. But at the same time, the prospects for stability in Asia look reasonable (Jim Steinberg and I wrote about how to make them more promising in our 2014 book, Strategic Reassurance and Resolve). And while the crisis in Ukraine is surely serious, it is at present confined to a relatively modest swath of that single country in Central Europe.

As such, a book focused on the future of the U.S. Army, and to a somewhat lesser but still important extent on the U.S. Marine Corps as well, should in my eyes take a balanced perspective. The goal is not to undertake a number of imminent large-scale missions; we have learned from Iraq and Afghanistan about the limits, challenges, and costs of such operations. But at the same time, the goals of maintaining deterrence of other great powers as well as smaller powers such as North Korea, and of being able to help stabilize key trouble spots that may be afflicted with various forms of civil warfare, terrorism, natural disaster, or other maladies, require substantial American ground forces. Drones, cyberwarfare, and special forces cannot do it all; pretending that we can turn our backs

Preface xiii on insurgency simply because Iraq and Afghanistan proved so hard is not viable either. In that sense, the book is at least a partial challenge to some of the logic of the Obama administration’s 2012 Defense Strategic Guidance and 2014 Quadrennial Defense Review, which deemphasized stabilization missions in American military planning.

Mine is not a radical book, relative to where the consensus in U.S. defense policymaking has been for most of the quarter century since the cold war ended. But it does sharply disagree with some of the ideas percolating through the American strategic debate today, ideas that would change the course of defense policy in a more pointed direction.

I am indebted to a wide range of colleagues, especially at the Brookings Institution but also beyond, in writing this book. Working at a defense center embedded in one of the best foreign policy programs of any think tank or university in the country has been an extraordinary privilege. It has helped me greatly with the tour d’horizon of the world’s countries and likely future hot spots that was integral to the methodology of this book project.

Bruce and Martin have been a joy to work with, and Strobe Talbott has been a collegial and brilliant leader of the institution for more than a dozen years. I am indebted greatly to Ian Livingston, as well as to Miranda Melcher, Jennifer Lawrence, and Brendan Orino, for research and other assistance at Brookings. Others in the Brookings defense center—John Allen, Bruce Riedel, Steve Pifer, Bob Einhorn, Vanda Felbab- Brown, Brad Porter, James Tyson—as well as visiting fellows from the military services, including John Evans and Chandler Seagraves, have been wonderfully helpful colleagues. So have Tanvi Madan, Steve Cohen, Cliff Gaddy, Harold Trinkunas, Richard Bush, Jeff Bader, Ken Lieberthal, David Dollar, Jonathan Pollack, Kenneth Pollack, Kathy Moon, Mireya Solis, Dan Byman, Tamara Wittes, Shadi Hamid, Salman Shaikh, Ye Qi, Jeremy Shapiro, Tom Wright, Bob Kagan, Fiona Hill, Beth Ferris, Suzanne Maloney, Charley Ebinger, Charlotte Baldwin, Julia Cates, Nicki Sullivan, David Wessel, Alice Rivlin, Ron Haskins, Bill Gale, Bill Galston, Phil Gordon, Amy Liu, Mark Muro, Bruce Katz, William Antholis, Steven Bennett, Gail Chalef, Elisa Glazer, Emily Perkins, Peter Toto, Sadie Jonath, Maggie Humenay, Ben Cahen, Doug Elmendorf, Karen Dynan, Lois Rice, Susan Rice, Roberta Cohen, Ted Piccone, E. J. Dionne, Tom Mann, Steve Hess, Marvin Kalb, Barry Bosworth, Henry Aaron, and many others.

xiv Preface

Beyond Brookings, my debts extend to many more, starting with Jim Steinberg and including Michael Doran, Peter Singer, Aaron Friedberg, John Ikenberry, Hal Feiveson, Frank von Hippel, Kim and Fred Kagan, Mackenzie Eaglen, Tom Donnelly, Michele Flournoy and Jim Miller and Kurt Campbell, Eric Edelman, Steve Solarz, Eliot Cohen, Vali Nasr, Steve Biddle, Max Boot, Michael Levi, Tom Christensen, Janine Davidson, Janne Nolan, Dick Betts, Ari Roth, Bruce Klingner, Bud Cole, Kathleen Hicks, Tony Cordesman, John Hamre, Eliot Cohen, Juan Carlos Pinzon, Diana Quintera, John Sattler, Ron Neumann, John Nagl, Duncan Brown, Larry Korb, David Gordon, Todd Harrison, Andrew Krepinevich, Frank Hoffman, Josh Epstein, Paul Stares, Tom McNaugher, Mike Mochizuki, Nick Lardy, David Shambaugh, Ashley Tellis, Michael Swaine, Karim Sadjapour, Ben Lambeth, Sean Zeigler, Andy Hoehn, Jim Dobbins, Mike Armacost, Bruce MacLaury, John Steinbruner, Carlos Pascual, Richard Haass, Jim Lindsay, Ivo Daalder, Barry Posen, Dave Petraeus, Stan McChrystal, Mike Meese, Barry McCaffrey, Maya MacGuineas, Woody Turner, Rebecca Grant, Bob Haffa, Richard Fontaine, Dan Benjamin, Kori Schake, Steve Hadley, Paul Wolfowitz, Robert Reischauer, Robert Hale, Jack Mayer, Wayne Glass, Neil Singer, Dave Mosher, Fran Lussier, Lane Pierrot, Michael Berger, Ellen Breslin Davidson, my many students over the years, and many members of Congress and the executive branch, who have inspired and taught me as well. Finally, Iam deeply grateful to the members of Brookings’s national security industrial base project and to Herb and Herbert Allen, as well as to many other members and supporters within the Brookings family.

CHAPTER ONE Introduction: Historical, Strategic, and Technological Context

WHAT IS THE FUTURE of land warfare, and of the world’s ground forces more generally? What can we realistically expect and project about the implications of interstate combat, civil conflict, and major humanitarian catastrophes for the world’s armies in the decades to come?

In recent years the U.S. national security debate has been turning away from these questions. Fatigued by Iraq and Afghanistan, rightly impressed by the capabilities of U.S. special forces, transfixed by the arrival of new technologies such as drones, and increasingly preoccupied with a rising China and its military progress in domains ranging from space to missile forces to maritime operations, the American strategic community has largely turned away from thinking about ground combat.! This is actually nothing new. Something similar happened after the world wars, the Korean War and Vietnam War, and Operation Desert Storm in 1991, as well. That last time, the debate shifted to a supposed revolution in military affairs. Many called for a major transformation in U.S. military forces to respond to that presumed revolution, until the 9/11 attacks returned military analysis to more practical and immediate issues. But now the strategic debate seems to be picking up about where it left off at the turn of the century—except that in the intervening fifteen years, remarkable progress in technologies such as unmanned aerial systems has provided even more grist for those favoring a radical transition in how militaries prepare for and fight wars.

Much of this debate is welcome. Even if futurists understandably tend to get more wrong than right in their specific recommendations, a debate in which they challenge existing Pentagon rice bowls is preferable to complacency. As long as the burden of proof is on those who would dismantle proven concepts and capabilities when proposing a whole new approach to military operations and warfare, a world of too many ideas is preferable to a staid, unimaginative one of too few. The history of military revolutions suggests that established superpowers are more likely to be caught unprepared for, even unaware of, new ways of warfare than to change their own armed forces too much or too fast.

That said, pushback against transformative ideas will often be necessary. We have seen many unrealistic military ideas proposed for the post-World War II U.S. armed forces, from the Pentomic division of the 1950s, which relied on nuclear weapons for indirect fire, to the flawed counterinsurgency strategies of the 1960s, to the surreal nuclear counterforce strategies from Curtis Lemay onward in the cold war, to the dreamy Strategic Defense Initiative goals of the 1980s, to the proposals for “rods from God” and other unrealistic technologies in the revolution in military affairs debate of the 1990s. As such, wariness about new ideas is in order. Even in a great nation like the United States, groupthink can happen, and bad ideas can gain a following they do not deserve.

One hears much discussion today about the supposed obsolescence of large-scale ground combat. Official U.S. policy now leans in that direction too, as codified in the 2012 Defense Strategic Guidance and 2014 Quadrennial Defense Review, largely as a result of frustrations with the wars in Iraq and Afghanistan. Accordingly, the 2012 Defense Strategic Guidance, released under the signature of then Secretary of Defense Leon Panetta, with a preface signed by President Obama, states flatly that “U.S. forces will no longer be sized to conduct large-scale, prolonged stability operations.”? The next year the Pentagon carried out a so-called Strategic Capabilities and Management Review that examined the option of reducing the Army to just 380,000 active duty soldiers.’ Subsequently the Ryan-Murray budget compromise of late 2013 and other considerations led to a less stark goal of 440,000 to 450,000 active duty soldiers. But the 2014 Quadrennial Defense Review again dismissed the plausibility of large-scale stabilization missions, though somewhat more gently, stating that “although our forces will no longer be sized to conduct large-scale prolonged stability operations, we will preserve the experience gained during the past ten years of counterinsurgency and stability operations in Iraq and Afghanistan.”* The emphasis changed somewhat, but the fundamental point was the same. Ground warfare, or at least certain forms of it, was not only to be avoided when possible— certainly, that is sound advice—but not even truly prepared for. That may be less sound advice.

There are lots of reasons to believe that, whether we like it or not, ground warfare does have a future, and a very significant one at that. Nearly three-fourths of the world’s full-time military personnel, almost 15 million out of some 20 million, are in their nations’ respective armies.° Most wars today are civil wars, fought within states by ground forces. Interstate wars are rare, but when they do happen, they generally involve neighboring states and generally involve a heavy concentration of ground combat. The United States may be far away from most potential conflict zones, putting a greater premium on U.S. long-range strike capabilities, including those of air and naval forces, than is the case for most countries. Yet the United States works with more than sixty allies and security partners, which tend to emphasize their own armies in force planning and tend to worry about land warfare scenarios within or just beyond their own borders. Iraq and Afghanistan revealed the limitations of standoff warfare and the problems that can ensue when the United States places severe constraints on its use of ground power (especially in the first few years of each conflict).

To paraphrase the old Bolshevik saying, we may not have an interest in messy ground combat operations in the future, but they may have an interest in us. Put differently, in contemplating the character and scale of future warfare, the enemy gets a vote, too.

As such, this book addresses two central questions. First, what is the future of land warfare, and of other possible forms of large-scale violence on land, in the coming decades? Second, what are the implications for the U.S. military, but particularly the U.S. Army and its three main components—the active duty Army, the Army National Guard, and the Army Reserve?

The U.S. Marine Corps falls partially within the scope of my analysis, but only partially. It has important capacities for substantial ground operations, to be sure. Yet it is also a naval force, being part of the Department of the Navy, as well as an expeditionary force, with an emphasis on rapid responsiveness for multiple smaller contingencies around the world. As with the special forces, therefore, its mission is somewhat different from that of the main elements of the U.S. Army—and its future size and structure seem less in doubt as well. Nonetheless, it is certainly relevant to the general subject of this book and is frequently discussed in the pages that follow.

Since the cold war ended, the U.S. Army, like much of the nation’s armed forces, has been built around the prospect of fighting up to two major regional wars at a time. That thinking has evolved, especially in the years when the United States was actually fighting two wars at once, in Iraq and Afghanistan (and in the process eliminating one of the threats on which the two-war scenarios had been premised, the government of Saddam Hussein). Former Secretary of Defense Donald Rumsfeld’s 2006 Quadrennial Defense Review began to shift the paradigm somewhat. The Pentagon’s 2012 Defense Strategic Guidance and 2014 Quadrennial Defense Review moved further away from a two-war construct without jettisoning it altogether. Now, in the second of the two overlapping wars, it is deemed adequate to “inflict unacceptable costs” on an adversary.° But the vagueness of the latter standard, deterrence by the threat of punishment, and changes in the international security order suggest that perhaps it is time to think afresh about the future of the U.S. Army and the other services. Planning for regional conflict will have to be a component of future force sizing, but with less specificity about likely foes than in the past and with a fuller range of considerations to complement the contingency analysis.

In this book, I begin with a blank sheet of paper about the future of land warfare and its implications for U.S. ground forces. The time frame is envisioned to go well beyond the current decade, into the 2020s and beyond. Where are future large-scale conflicts or other catastrophes on the world’s land masses most plausible? Which of these could be important enough to necessitate the option of a U.S. military response? And which of these could in turn require significant numbers of American ground forces in their resolution?

Put differently, one frequently hears the adage that the United States does not have a good track record in predicting its future wars. Some even turn the saying on its head, saying that yes, we do have a good track record—a perfect one, in fact—of getting the future wrong. Afghanistan, Iraq, Vietnam, Korea, and indeed the world wars (not to mention the American Civil War) were not accurately foreseen by most strategists or planners.

Yet it is still important to examine how the configuration of worldwide threats, resources, centers of economic power, overseas political dynamics, and American strategic interests could produce conflict in the future. Strategists may not know when or where. But having a sense of the character and likely magnitude of any future conflict is essential. To paraphrase Eisenhower, moreover, the planning process is essential, even if any plans themselves that we manage to develop may not be precisely relevant. The alternative to analysis is to have future forces and Pentagon priorities determined by guesswork, bureaucratic and political inertia, and faddishness about new technologies, as well as by apparent new trends in conflict. We cannot predict the future. But for purposes of understanding the necessary size and shape of the future American military, including its ground forces, it is important to try to delimit it as much as possible. Historically, the United States has had several periods of coherent grand strategy—the Monroe Doctrine in the nineteenth century, victory in Europe first and in the Pacific later in World War II, containment in the cold war—and the nation as well as its allies should aspire to some coherence and cogency in the future as well.’

Some would counsel against preparedness for plausible military missions on the grounds that by being prepared, we might stray into conflicts that would have been best avoided. The 2003 Iraq War may be a recent case In point—a “war of choice,” in Richard Haass’s pithy depiction, that surely would not have been undertaken without a ready and fairly large standing military.* But for every such case in U.S. history, there are probably several—including the two world wars and the Korean War— in which lack of preparedness proved an even greater problem. Moreover, in Iraq and Afghanistan, improper preparation for a certain type of fighting arguably made the initial years in both these wars far less successful than they might have been. Nor is it so clear that the United States is really spoiling for military action abroad. Americans may not be as restrained in the use of force as they often like to believe themselves to be. Yet at the same time, casualty aversion—and, more recently, a national souring on the kind of ground operations conducted in Iraq and Afghanistan—impose important constraints on action as well. Deliberately staying militarily unprepared for plausible missions as a way of avoiding unsuccessful military operations abroad thus seems an unwise and highly risky strategy for the nation.

The time frame of the analysis is roughly 2020 through 2040—beyond the immediate budgeting challenges of the next appropriations cycle and five-year defense plan but not so far off as to be disconnected from current policy decisionmaking. Of course, there will be surprises between now and 2020, but some of the main drivers of international conflict can probably be identified.

Several countries loom large in the pages that follow. They include the world’s largest, most industrialized, most militarized, and most populous nations. These states have the wherewithal to cause or experience security challenges that could pose systemic and large-scale disruptions to the global order and to American interests. Prominent examples include Russia, China, India, Pakistan, Iran, Egypt, Saudi Arabia, Nigeria, and Mexico. What are the prospects that some of these countries could attack their neighbors, turn on themselves in large-scale civil warfare, suffer massive tragedies of some type, lose track of nuclear materials or other highly dangerous agents, or otherwise create a major international crisis that could not be easily ignored?

The analysis is not confined to traditional war scenarios. It also looks at complex humanitarian or relief activities of various types, some of which could involve an element of violence but others of which may not. It considers, for example, the chances that large, populous parts of certain countries or regions could suffer enormous tragedy that would dwarf the world’s worst disasters to date and necessitate massive and sustained relief efforts. Such contingencies could have significant implications for the global order and thus should be factored into American strategic thinking and military force planning.

The policy implications of these kinds of analyses are very important. They go beyond predictable, if major, decisions about matters such as when to replace the Abrams tank, or how many brigade combat teams to retain in the U.S. Army Active and Guard force structure, or how to reshape and reconfigure such combat units. Even broader and more fundamental questions arise. Should the United States retain a large active duty army, as it has since World War II, or revert to an earlier model of a citizens’ army, with greater reliance on the National Guard? Does the U.S. Army, along with the Marine Corps, need to retain a large-scale expeditionary capability of dominating maneuver warfare virtually anywhere on Earth? How great should America’s reliance on allies be in the future?

This book concludes with such questions. I ultimately argue for an army not unlike that described in the Obama administration’s current plan—roughly a million soldiers, with about 450,000 on active duty. However, the mathematics behind this force-sizing construct are different from those of the Pentagon today. As noted, today’s Department of Defense retains some elements of a two-war capability. My framework would not. Instead, it would plan for a single decisive war, combined with a possibly prolonged U.S. role in two simultaneous, multilateral missions, which could involve counterinsurgency, stabilization, deterrence, or a major disaster response. It might be described as a “1+2” paradigm, for one war, together with two smaller and more multilateral but potentially long and complex operations.

The book does not begin with that issue, however. Instead, after a brief review of the history of U.S. ground forces in this chapter and observations about U.S. grand strategy, I attempt to determine where large-scale violence or mayhem on land is most plausible and where it would be most consequential strategically. I then ask which contingencies could require a large-scale U.S. response with ground forces, rather than some other mix of military tools. In many cases the U.S. preference would surely be—and should surely be—to avoid direct involvement in any operation with U.S. forces if at all possible. However, in light of trends in military burden sharing worldwide and the irreplaceability of American leadership for many difficult military operations, it is quite plausible that in some cases, direct U.S. intervention as part of a coalition could prove necessary. The book concludes with implications for the force postures and budgets of the U.S. ground forces.

A HISTORICAL SKETCH OF AMERICAN GROUND POWER

Throughout its history, the United States has been influenced by dueling paradigms in sizing and shaping its ground forces. On the one hand, it has retained a somewhat romanticized image of the gentleman soldier, or the farmer-soldier, who takes up arms only when his country’s security demands it and returns to civilian life once the shooting stops. This narrative, grounded in part in America’s geographic luxury of being protected from potential foes by two oceans and in its history as a land of

Figure 1-1. Size of the U.S. Army throughout History, 1860-2014

Number of active-duty (uniformed) personnel (million)

Sources: U.S. Army Center of Military History, “American Military History,” vols. 1 and 2 (www.history. army.mil/books); National WWII Museum, “By the Numbers: U.S. Military” (www.nationalwwamuseum. org/learn/education/for-students /ww2-history/ww2-by-the-numbers/us-military.html); and U.S. Census Bureau, “Statistical Abstract of the United States,” Department of Defense Personnel (www.census.gov/ compendia/statab/).

immigrants trying to escape the conflicts of the Old World, idealizes the local militia as much as the huge institutional army. It fit fairly well with reality in the United States, with a couple of very notable exceptions, for most of the country’s first 140 years (see figure 1-1 on the size of the U.S. Army over the course of most American history).

This image of the reluctant warrior, and the demilitarized nation, accords with the life of the nation’s first commander in chief and president, George Washington. General Washington was more than happy to resign his military commission after the Revolutionary War and resume the kinds of economic pursuits that had always been his main preoccupation. This preference for the plow over the sword earned Washington the nickname of the American Cincinnatus, after the Roman farmer-soldier who returned to his fields whenever military circumstances allowed.’ More broadly, Washington’s example helped foster and reinforce the historical theme of a United States uninterested in Europe’s wars of the eighteenth and nineteenth centuries and preferring to avoid them altogether, as typified in John Quincy Adams’s admonition to Congress in

1821 about championing freedom abroad without actively seeking to impose it.'° Washington’s Farewell Address had voiced similar views. It contained the following counsel to the union’s states:

Hence, likewise, they will avoid the necessity of those overgrown military establishments which, under any form of government, are inauspicious to liberty, and which are to be regarded as particularly hostile to republican liberty. In this sense it is that your union ought to be considered as a main prop of your liberty, and that the love of the one ought to endear to you the preservation of the other."

This attitude was reflected as well in the rapid demobilizations of the nation’s armed forces after the Revolutionary War. One result was the poor preparedness of the nation for the War of 1812, when the army had fewer than 10,000 soldiers at the outbreak of hostilities.“ The army roughly tripled in size in the course of that war but then declined back to a paltry 11,000 or so by 1830.% Small standing forces were the norm in the Republic’s early decades in general. Even the Mexican War in the mid-to-late 1840s typically involved only 5,000 to 10,000 U.S. troops out of a total ground force not much larger." At the outbreak of the Civil War, the U.S. Army numbered just 17,000 in all.!° After the Civil War, when some 3 million Americans served, mass demobilization occurred again.'® From the 1870s until the Spanish-American War, the full-time army numbered fewer than 30,000 soldiers. At century’s end, the U.S. Army was less than a tenth the size of any major European power’s ground forces.'”

Despite occasional colonial ambitions from Mexico to Cuba and the Philippines, most of early U.S. history fostered the image of a nation that was not militarized in the way of European powers of the day. It is striking that by the late 1800s, the United States had become easily the second most populous major power after Russia, with an 1890 population of more than 60 million (Russia’s was about 115 million; Germany’s was about 50 million, with other major European states and Japan each in the range of roughly 30 million to 40 million). Yet the United States had only some 35,000 military personnel (including its Navy and Marine Corps), at a time when European powers typically had 200,000 to 750,000 men at arms.!š

Subsequently, as the United States began to focus on building up stronger armed forces, much of the effort went into building a strong battleship-oriented Navy rather than a more capable army. This dynamic, which began in the 1890s, was motivated by the writings of Alfred Thayer Mahan, the global ambitions awakened by the Spanish-American War, and the political leadership of Theodore Roosevelt, among others."

These realities changed in the twentieth century, of course, but only fitfully. At the outbreak of World War I, the U.S. Army was only about 100,000 strong. After the war it was scaled back again, to less than 140,000. In the early 1930s the U.S. Army ranked seventeenth in the world in size, behind the armies of Portugal and Belgium. It was generally strapped for funds for equipment and training as well. Indeed, while its school systems and certain other characteristics were becoming more professional and serious, the army of the 1920s and 1930s was in some ways the most disengaged from combat of any army in the nation’s history since there were no longer battles against Native Americans (or Mexicans or Spanish) to wage.” Even as the decade of the 1930s unfolded and Europe lurched toward general war, in 1938 the U.S. Army was only 165,000 strong, nineteenth largest in the world.*? Much of the intellectual energy directed to America’s armed forces was trained on new possibilities in naval and air combat, sparked by thinkers such as Billy Mitchell, rather than on ground armies.”*

Through the end of the nineteenth century, state militias were often a very real rival to the regular army for political support and resources. They had been important in the Revolutionary War and remained so thereafter. Indeed, in its Articles I and II, as well as in the Second Amendment, the Constitution not only made militias permanent but explicitly recognized and codified their independent standing separate from the army.” At the onset of the Spanish-American War, the sum total of all militias exceeded 100,000 personnel, or about four times the total number of soldiers in the Active Army.