This study provides preliminary observations and insights on the character and conduct of protracted great-power war.1 It finds the U.S. Department of Defense is giving insufficient attention to preparing for such wars. While the probability of an extended great-power war may be low, the costs involved in waging one would likely be extraordinarily high, making it an issue of strategic significance for senior Defense Department leaders.
Arguably the best way to avoid these costs is to demonstrate to great-power rivals that the United States is capable of prevailing in a protracted conflict. Once the United States became an active world power, in the early 20th century, a great deal of intellectual effort and considerable resources were devoted to planning for an extended great-power war. The primary purpose of these efforts was not to fight such a war but to avoid one, by discouraging prospective enemies from believing they could win. Even during the Cold War, when both superpowers possessed large nuclear arsenals, successive U.S. administrations sought to demonstrate to the Soviet Union that the United States could wage an extended conventional war.
Following the Cold War, planning for protracted great-power war contingencies was essentially abandoned. Now, however, with the rise of revisionist China and Russia, the United States is confronted with a strategic choice: conducting contingency planning for a protracted great-power conflict and how to wage it successfully (or, better still, prevent it from occurring), or ignoring the possibility and hoping for the best. Should they choose the former course of action, U.S. defense leaders and planners must understand the characteristics of contemporary protracted great-power war, which are likely to be far different from those of both recent conflicts and World War II—the last protracted great-power conflict.
Why Do Great-Power Wars Become Protracted?
Throughout history, several factors have contributed to the protraction of wars between great powers. One factor is great powers’ strategic depth, which could make them difficult to defeat in a short period of time, or at all, as World War II Germany discovered when it invaded Soviet Russia in 1941. Another cause of protraction is belligerents’ inability to strike directly at their enemies, as occurred in the Napoleonic Wars when Britain and France—the “whale” and the “elephant”—lacked the means to confront the other directly. In World War I, even after the horrific losses incurred by the great-power belligerents early on, a negotiated peace proved elusive, due in part to their need to achieve a victory sufficient to justify the enormous human suffering and material costs already sustained. Still another cause of protraction centers on the interest of third parties in keeping combat going. In making his pre–World War II pact with Adolf Hitler, for example, Soviet dictator Joseph Stalin sought to benefit from a war of exhaustion between Nazi Germany and the Anglo-French alliance.
A belligerent may also be encouraged to continue fighting in the hope that a major neutral power will come to its aid or that its enemy will lose the will to continue. For example, in the former case, during both world wars Britain was encouraged by the prospect of the United States’ entering the war on its side. With regard to the latter case, during the U.S. Civil War the Confederacy continued to resist in part from a hope that a “peace candidate” would win the 1864 U.S. presidential election. The belligerents’ war aims may also prolong a war. In the U.S. Civil War, for example, the two sides’ aims were fundamentally at odds: The North sought to compel the rebellious states to rejoin the Union while the South sought to secede from the United States, leaving no room for compromise.
A contemporary great-power war would be profoundly different in several ways from earlier such wars. The time elapsed between today and the start of World War II, 80 years, is roughly the same as the time between America’s entry into World War II and the start of the American Civil War. Just as the combatants in the Civil War would have felt greatly out of place at Pearl Harbor, those who fought in World War II might feel disoriented in a contemporary great-power war. Given the continued rapid advance of technology, a future protracted great-power war would likely produce surprises, some of strategic significance.
Moreover, with the advent of nuclear weapons, wars between great powers can be protracted only if political constraints are imposed on vertical escalation. In contrast to the situation during past great-power wars, a modern belligerent great power’s problem would not be an inability to bring military power to bear on the enemy but the knowledge that in so doing it would likely escalate the war to mutual catastrophic destruction. Thus belligerents would have a strong incentive to practice mutual restraint. Whether they would be able do so is problematic. If they succeeded, the victors in such a war would not be able to impose anything like unconditional surrender on their enemies, as occurred in World War II. Regime change would be out of the question. Both sides would live to continue the competition. The result would be less a peace than the start of the next round in an open-ended struggle for geostrategic advantage.
Waging Protracted Great-Power War
While striving to avoid nuclear disaster, the great powers in a protracted war would still be seeking to improve their position in a war of limited means and limited ends. Preparing for (and thus deterring) protracted great-power war would require some significant rethinking of U.S. defense strategy, particularly with respect to escalation. One way for the United States to avoid losing a limited war or having the enemy escalating to “Armageddon” would be to maintain a U.S. advantage in the ability to vertically escalate the conflict (i.e., its level of violence). The ability to prevent an enemy from exploiting horizontal (geographic) escalation (e.g., by economic blockade or by seizing ally territory or U.S. overseas assets) would also likely prove a major advantage.
To avoid escalating a war unintentionally, senior U.S. defense decisionmakers would have to understand how rival great powers view escalation, and how those powers’ views might differ from their own. This task would be complicated by the introduction of advanced weaponry, both nuclear and non-nuclear, that is eroding the once relatively clear “firebreak” between these weapons. Preventing escalation might also be complicated by third parties seeking to trigger escalation through difficult-to-trace attacks, such as in space, in cyberspace, or on the seabed. Given the difficulty in identifying the source of such attacks, they could be interpreted as an escalation by the enemy.
If the United States were unable to defeat its enemy at the point of attack, and sustain its defense over an extended period of time, or if it were unwilling to risk escalating the level of violence to do so, it might find itself gravitating toward horizontal escalation to gain advantage. Thus a strategy of exhaustion would likely be pursued, rather than a strategy of annihilation or attrition.
A number of political issues could exert a significant influence on the character of a protracted great-power war. One issue concerns whether the war began on politically favorable terms. History suggests it might be worth suffering a short-term military reverse to gain the benefits of operating on the moral high ground.
Allies might also emerge as a major source of U.S. competitive advantage. In an extended conflict with another great power, the demand for American combat forces would almost certainly far outstrip the supply. Consequently, the U.S. need for capable allies would likely expand and endure. Political efforts aimed at securing and maintaining ally support, and denying the enemy the support of key potential allies, could exert a profound effect on the war and its outcome. In pursuing a strategy of exhaustion, an important factor in U.S. strategy would be its ability to leverage its allies’ assets so as not to exhaust its own.
From an operational standpoint, preparing for (or deterring) a protracted war with another great power would require the United States to improve the military balance. The U.S. military would have to shift away from the expeditionary posture it emphasized following the Cold War and focus more on buttressing its so-called contact- and blunt-layer forces—adopting a more forward defense posture. Toward this end it should begin implementing the “Archipelagic Defense” concept in the Western Pacific, and creating anti-access/area-denial (A2/AD) defenses in the Eastern Europe frontline states.
If a stalemate occurred at the enemy point of attack, or if U.S. and allied forces were unable to defend successfully, they would need to be capable of waging war effectively in other places of their choosing. This would likely involve escalating the conflict horizontally, to include waging economic warfare. At some point in the conflict the United States might need to conduct counteroffensive operations, especially if it had ceded areas of strategic value. Toward this end, it would need to develop and perfect new warfighting concepts designed to suppress enemy A2/AD forces, execute forcible entry operations, and conduct sustained ground offensive operations supported by forces establishing friendly A2/ AD defensive zones.
A protracted war between great powers would likely find the belligerents seeking to reduce their adversaries’ warmaking potential through economic warfare, as part of a strategy of exhaustion. Actions might involve blockade operations, as well as commerce-raiding operations against an enemy’s undersea economic infrastructure. Given the rise of global logistics chains and just-in-time inventory systems, small disruptions in the velocity of trade could trigger large-scale economic dislocations.
Even if the war were waged below the nuclear threshold and great-power homelands were accorded partial sanctuary status, given modern conventional, biological, and cyber weaponry, the level and scope of destruction in a great-power war would be far greater than anything the American people have experienced. Under these circumstances, the social dimension of strategy—the ability to sustain popular support for the war effort, along with a willingness to sacrifice—would be a crucial factor in the United States’ ability to prevail.
The United States’ current ability to surge and expand rapidly the production of military equipment is questionable. Among other problems, little in the way of detail is known regarding where production bottlenecks are, the types and quantities of raw materials that should be stockpiled, and the availability of skilled labor that would be required to expand production of war materiel.
Improving the U.S. Position
Senior Defense Department policymakers should prioritize the following initial, modest steps to improve the United States’ ability to deter such conflicts or, if deterrence fails, to wage war and prevail.
In a democracy, it is essential to develop and sustain popular support for a long-term competition that involves periods of peace but also the possibility of protracted conflict between the great powers—especially if a key U.S. security objective is to avoid such a conflict and the enormous costs it would almost certainly incur in waging it. Toward this end, an effort should be made to explore in depth the effects of protracted war on the United States and on other great-power societies. Senior national security leaders, including the commander in chief, must make the case for U.S. defense preparedness to the American people.
The Defense Department should plan for protracted great-power war developing planning scenarios, conducting war games to evaluate the scenarios, and identifying key requirements that emerge from these efforts. The overarching purpose, of course, is to craft a strategy for deterring such wars, or waging them effectively if deterrence fails. Thus the effort should identify and address gaps in the horizontal and vertical escalation ladders, and how best to address them.
Promising Research Areas
This paper represents a modest “first cut” at the challenge of deterring or successfully waging a protracted great-power war. Its findings are illustrative, not conclusive. The Defense Department, with support from other relevant Executive Branch departments and agencies, and from experts in the strategic studies community, should undertake in-depth analyses before major decisions regarding policy, strategy, and resource priorities can be made. Among the research topics meriting priority consideration are the following:
Given the importance of deterring great-power rivals from believing their interests can be advanced through prevailing in a protracted war, the Defense Department and Intelligence Community should give priority to assessing how rival great powers— China and Russia in particular—view protracted war with the United States and its ability to wage such a war effectively. The same can be said regarding how these revisionist powers view escalation.
With guidance from senior Defense Department policy-makers, the military leadership should develop a comprehensive set of defense-planning scenarios to assist and inform planning. This approach would be similar to the “color plans” developed to support planning between the two world wars.
The Role of Allies
An essential part of planning for protracted great-power conflict involves assessing the role U.S. allies and security partners might play. Senior U.S. national security policymakers need to identify what they want of America’s allies—not only in terms of increased spending, but with respect to specific capabilities, force postures, and basing access—as well as what those allies may need from the United States.
The Long-Term Competition
Assuming a great war did not escalate to Armageddon, it would end with a negotiated settlement. Thus, there is a need to explore war-termination strategies. The objective of this effort should be to determine how best to position the United States to compete effectively in what would be an open-ended postwar competition.
Several net assessments should be accorded priority:
- The Strategic Balance. To enhance U.S. senior decisionmakers’ understanding of escalation dynamics, the Defense Department’s Office of Net Assessment should expand its traditional focus on the nuclear balance to take account of other key elements of the strategic balance, including precision-strike forces, cyber payloads, early warning and command-and-control force elements, and advanced air and missile defenses.
- The Mobilization Balance. This assessment should focus on the Western Pacific and European theaters to determine whether of a mobilization race between U.S. forces and their allies and rival state military forces would create incentives or disincentives for the revisionist great powers to seek to achieve their goals through overt aggression.
- The Economic Warfare Balance. The focus here should be on ways the various forms of economic warfare, such as maritime and cyber blockades, traditional and seabed commerce raiding, and cyber warfare, would affect the military balance in a protracted great-power war.
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