After two decades of focusing on counterinsurgency and counterterrorism, the US Department of Defense has worked to reorient toward the possibility of conflict with a near-peer competitor. While the department has progressed in this area, one sub-set of preparation has been largely ignored: the defense enterprise needs to confront the non-zero possibility that it may have to fight not only a conventional war, but a protracted conventional war against another great power in the coming decades. To that end, the Department of Defense needs to revisit and question assumptions that it may still maintain about protracted warfare in order to prepare the United States for the potential of extended conflict with a near-peer adversary.

While the definition of conventional war is widely understood, that of protracted conventional war has been harder to come by. Conceptualizing it is even more difficult now, as the US understanding of war appears to have baked-in assumptions that it will be—because it is objectively desirable—a short war. In the late 1980s, RAND researchers considered any war with the Soviet Union that lasted more than thirty days to be protracted. More recently, Office of Net Assessment alum Dr. Andrew Krepinevich set a standard of any war lasting more than eighteen months as being protracted. This article considers any war between sovereign states that is measured in months or years as opposed to weeks or days as a protracted conventional war.

The United States’ last experience with fighting a war against a peer that could be called protracted and conventional—World War II—was almost seventy-five years ago. Many of the assumptions the United States still holds about protracted war are just as old. In cases where lessons from decades past may still be valid or have regained utility, they will need to be reconsidered in the current context. Failure to do so results in a paradoxical situation where the defense community embraces outdated assumptions, but fails to identify lessons that are still relevant to the current age. Several of the most notable—and potentially dangerous—faulty assumptions, the institutional manifestations of which seem baked in to the way that DoD approaches the problem of conventional warfare in general, warrant particular examination: that the United States will be the master of the new domains of warfare; that the potential for “decisive battle” still exists; that ample supplies of critical war material will always be available; and that the US homeland is untouchable.

Master of Its Domain

One of the most dangerous assumptions is that by the time the next major conflict breaks out, the United States will be able to achieve and maintain dominance over emerging domains of warfare like space and cyberspace, as well as in the more amorphous battle for information. This assumption is not exclusive to a protracted war, but becomes all the more critical in a conflict with a peer adversary.

Looking back to World War II, traditional measures of domain superiority did not help the Allies, even as they held advantages. In 1940, on paper, the French Army was widely considered the strongest military in the world. France had more tanks than Germany, with several models superior to anything the German Army possessed. Ultimately, however, Germany had the superior concept of operations of how to use the tanks and other new weapons in its Blitzkrieg. The United States cannot assume it will be the master of new tools from the onset of war, even if the individual tools themselves are technologically or even numerically superior to those of the adversary. Moreover, lacking any significant examples the relevant measures of superiority for domains like cyber and space are essentially unknown. A lack of experimentation, clinging to outdated concepts, and ignoring new or different lessons all factor in to an inability to imagine new concepts for old capabilities or disruptive capabilities in the face of “proven” concepts.

Going back further, World War I offers the same lessons for all sides. Before 1914, all major participants possessed most of the new weapons that would shape that war—machine guns, aircraft, long-range artillery, and others. All had been used before in grisly, but institutionally ignored, conflicts that previewed the slaughter to come. Despite this, these armies failed to understand or anticipate how these weapons would be used at scale, in the service of a large operational concept, or in the specific environment they would encounter in Europe from 1914 until 1918. Aircraft, for example, were at first used mainly for reconnaissance rather than bombing or air superiority. The warring parties would not fully understand some weapons that emerged during the war until the next one—as the tank in 1940 exemplifies. Training and experimentation can help to mitigate these risks, but the United States may not know how or which new domains or domain-specific capabilities will factor into the next major war until it is in the thick of it. Balancing preparedness with flexibility will be crucial.

An increasing number of voices are questioning the United States’ general military superiority vis-à-vis a near-peer competitor. If the United States is to prepare as much as possible for a potential near-peer protracted conflict, considering such questions can only be the beginning of a shift in how DoD approaches near-peer conflict, not the end. There must be an open, rigorous, intellectually honest, and continuous professional debate about the character of future war and a healthy fear that the most important changes may come from new or nontraditional domains.

The Lure of “Decisive Battle”

Another assumption held from even further back in the modern age is the idea that militaries should seek decisive battle as the key not only to a successful campaign but to a short war. Historian Cathal Nolan holds this as a central theme in his book, The Allure of Battle. The desire for a decisive battle is understandable—while under some circumstances, a drawn-out conflict could be advantageous, it is generally something states wish to avoid. Where problems arise is when a state hopes for the best—a quick and decisive war—and fails to account for the full range of alternatives, one of the worst of which is a protracted war.

In the case of the United States, the proposition that a military victory can be both rapid and decisive (militarily at least) was ingrained in Operation Desert Storm in 1991, and subsequently was reflected in the “Two Major Regional Conflicts” (Two MRC) force-sizing construct. This construct was geared toward what was thought to be the new post–Cold War norm: regional threats like North Korea, Iran, and Ba’athist Iraq. As characterized in the Secretary of Defense’s Annual Report in 1996, the Two MRC construct called upon the United States “to fight and decisively win two MRCs that occur nearly simultaneously.” With various modifications, this served as the US force-sizing construct until the 2018 National Defense Strategy shifted focus to defeating one great-power adversary and deterring another.

Though the Two MRC construct is no longer the reference for US force planning, its impact on military thinking will not soon fade. The United States has largely conflated the idea of war with the idea of the decisive battle, and DoD has come to see war in itself as being a decisive battle. Its influence also lingers in that it provides a poor framework for how to address an era in which the United States is confronted both by multiple near-peer adversaries and a number of regional adversaries, all of which may attempt to take advantage of US distractions in another part of the world to make gains in their own.

Both sides in both world wars sought the decisive battle. It took four years of slaughter during World War I—and a German Army bled dry of personnel by casualties, desertion, and finally mutiny—to end that conflict. World War II ended only after the Allies had inflicted prolonged destruction on the Axis powers, culminating in dropping the atomic bomb on Japan and the long-term occupation of Axis countries. As Nolan argues, single battles in themselves do not accomplish much other than speeding the attrition of supplies and manpower. As he writes in The Allure of Battle, attrition becomes the “overwhelming strategic reality” in large-scale, protracted conflicts like the world wars. The United States must realize that war may not end decisively, with examples of decisive wins in recent history being small victories in Grenada or Panama, decisive military victories with political indecisive endings like Desert Storm, or ones that are still ongoing in Iraq and Afghanistan where the outcomes are debatable. Accepting less than decisive outcomes might be preferable to the cost of reaching for one, of risking defeat, or of the dangers of miscalculation and escalation.

The Arsenal of Democracy

DoD would also benefit from questioning assumptions about supplying a protracted conventional war in the twenty-first century. Chief among these is that the United States can simply mobilize its economy as it did for both world wars. World War II saw the nation retool its economy and churn out warships, tanks, aircraft, guns, and other equipment. DoD’s existing plans for mobilizing the economy in a large-scale war or crisis takes for granted that industry can be not only mobilized, but mobilized quickly. Joint Publication 4-05, Joint Mobilization Planning states that the industrial base will be “expanded,” will “surge production,” and will “accelerate output” without detailing how the expanding, surging, or accelerating will be accomplished. It only mentions in passing obstacles and side effects with little or no discussion of how to mitigate them.

While such nationwide mobilization is not necessarily impossible, the modern economy has made this increasingly difficult, time consuming, and expensive. As Mark Cancian wrote in War on the Rocks, today’s economy is optimized for efficiency, not for massive wartime production. A major conflict with a near-peer adversary would rapidly burn up the United States’ and allies’ relatively small stockpiles of munitions and equipment more quickly than industry could keep up with—especially as supposedly low-intensity wars have rapidly used up munitions at a faster rate than the military’s logistics systems can accommodate.

During the past twenty years of counterinsurgency and counterterrorism operations, the United States has come to rely on “just in time” logistics to supply its forces in these low-intensity operations against irregular enemies. This is also true of civilian supply chains, as the 2020 COVID-19 pandemic has demonstrated. When a protracted crisis hits, “just in time” logistics simply lacks resilience against shocks and disruptions. During a protracted conventional conflict where getting supplies to their destination will be buffeted by shocks and disruptions, “just in time” could end in disaster. However efficient this method may be for companies during peacetime, cutting costs and healthy profit margins do not win wars.

Fortress America

Since the mid-nineteenth century, America has enjoyed two oceans to protect against most adversaries and competitors. While Japan inflicted a devastating attack on Pearl Harbor in 1941, after that initial attack, neither Germany nor Japan could repeat such success on US soil during World War II. The Axis powers could touch the continental United States in some ways for the rest of the war, but they were relatively minor and ineffective, aside from attracting some headlines and triggering local fears.

The United States can no longer primarily depend on geography for protection. Nor can it assume that the threat of potential nuclear escalation would dissuade a great-power adversary like Russia or China from launching a non-nuclear strike against the homeland under the right circumstances or pressure—which could be created during a protracted conflict. DoD leadership is gradually realizing the homeland is at risk from near-peer adversaries, although some were realizing it long before the return to great-power competition.

Russia and China now field sophisticated conventional strike capabilities that hold the continental United States in their ranges. They could deploy conventionally armed cruise missiles—such as Russia’s 2,500-kilometer–range, submarine-launched Kalibr—from air, land, and sea platforms at a comfortable distance. The Russian state arms export agency advertises an export model of the Kalibr—the Klub-K—that operates from a nondescript shipping container. Strikes on the US homeland could not only reach US military forces and citizens—they could cripple key supply and transportation hubs; damage factories of key weapons, munitions, other supplies and technology; strike infrastructure; and inflict terror and panic. This is all to say nothing of potential unconventional kinetic threats from enemy special operations forces or aligned third-party groups.

Conventional kinetic attacks are not all that threaten the US homeland. Nonkinetic capabilities like cyberattacks have already damaged the United States and others, with both key military and civilian networks and infrastructure targeted. If intensified, cyberattacks could challenge not only US abilities to wage war, but also to function as a nation, and could raise questions of escalating the conflict into physical domains with conventional or even potentially nuclear strikes in retaliation. US adversaries have also already demonstrated a willingness and ability to effectively employ psychological warfare, using influence operations to subvert narratives and sow social division. In a protracted conventional war against a great power determined to win, one must assume that a US adversary can and will strike the homeland in multiple ways.

The Way Forward

Across the world, multiple conflicts offer possible previews of the next major war, much in the same way the Russo-Japanese War did for World War I or the Spanish Civil War did for World War II. Conflicts in Libya, Syria, Ukraine, and Yemen—among others—demonstrate how assumptions about protracted war are being challenged by the use of unmanned systems, misinformation and influence operations, and kinetic and nonkinetic attacks on infrastructure and industry. The back-and-forth setbacks for the warring parties, the displacement of civilians, and the long durations of these conflicts all offer warnings.

Despite such warnings, there has been almost no discussion of protracted conventional war in the national security community, let alone within DoD. Some individual analyses have drawn attention, such as Dr. Krepinevich’s recent and detailed report on fighting a protracted war with a near-peer competitor. Work like Dr. Krepinevich’s is an excellent start, but disparate, individual voices are not enough. A cultural shift must occur within DoD and the national security community on what the United States can expect from a twenty-first-century version of protracted conventional war with a near-peer adversary, and those communities and stakeholders must examine how the country is prepared for such a conflict. The defense enterprise will need to identify and change how it does business in order to better prepare for protracted war—both internally, and externally with US allies and partners that would be indispensable in such a conflict. Otherwise, DoD must be willing to assume high levels of risk in some areas if it is unable to reprioritize resources.

Patrick Savage is a research associate in the Joint Advanced Warfighting Division of the Institute for Defense Analyses. He holds a master’s degree in security studies from the Edmund A. Walsh School of Foreign Service at Georgetown University.

The views expressed are those of the author and do not reflect the official position of the Institute for Defense Analyses, or of the United States Military Academy, Department of the Army, or Department of Defense.

Image credit: Staff Sgt. Gregory Stevens, US Army