The Army and the Future of the International System


From Parameters, Summer 1994, pp. 85-97.

Americans are inherently practical people, preferring the immediate and the tangible to the long-range and the intangible. This characteristic has brought us immense success in all realms of life, but it also complicates the process of crafting a coherent national security strategy. By focusing too much on the immediate and the tangible, we can easily lapse into strategic myopia, thus simply postponing tough decisions and allowing small threats to grow into large ones. This is particularly true during periods of strategic transition such as the current one.

A huge array of factors must be considered as we attempt to design a coherent post-Cold War national security strategy. These include not only the traditional elements of strategy such as politics, economics, and the military balance, but also newer forces such as social trends, value changes, demographics, mass psychology, the expansion of communications and information technology, and environmental concerns. But of the factors that will shape future US national security strategy and the military force required to execute it, the most amorphous and difficult to analyze is the nature of the international system itself. This is the foundation for all strategy.

Thinking at such a high level of abstraction can seem alien and esoteric to security professionals confronting the press of day-to-day problems where in-baskets rather than international systems take priority. System-level analysis is intensely, sometimes overwhelmingly complex. The tendency, then, is to avoid it in favor of more immediate and seemingly easier issues. But over the long term, the macro-level nature of the international system may be the most vital element of a coherent strategy. It is simultaneously ethereal and relevant, driving consideration of the appropriate force structure and procedures for applying national power. For this reason, astute strategists simply must speculate on this topic.

At this point, we cannot know precisely what form the post-Cold War international system will take. We can, however, develop a range of possibilities based on past patterns and current trends. These can be distinguished by a number of factors, including:

Most important, once a range of feasible alternatives is developed, we can then discern the security implications of each and thus approach the task of long-term strategy formulation with at least some basic guidelines.

Unipolar Systems

Unipolar systems represent the ultimate concentration of power. In them, the core consists of one unit; the remaining elements of the system are secondary powers or part of the periphery. There is no historic example of a global unipolar system, only regional ones such as the Roman, Mongol, and Chinese empires. But since the current global configuration of power is loosely unipolar, it is possible to conceive of a post-Cold War system in which the United States remains the sole superpower. After all, no other state is likely to challenge American military superiority in the near future, and, while the other elements of national power are more dispersed throughout the system, no other state is a first-tier actor in all the elements of power.[1] But in the modern world, a sound argument can be made that unipolarity is temporary and abnormal because modernity has sped up the systemic cycles of the concentration and dispersion of power. Unipolarity also runs counter to the American strategic tradition.[2] After all, the dispersion and balancing of political power forms the absolute essence of our own domestic political system, and thus we prefer a similar configuration in the international political system.

Given that the United States is unlikely to sustain the exertions of hegemony, a unipolar system in which some other unit forms the core could emerge. In at least the mid-term, this is unlikely unless there is a dramatic collapse of American power or will, but it is still feasible. The new hegemon could be a regional coalition or bloc such as the European Community or a supranational global organization like the United Nations or its descendent. Less likely but still worth mentioning is the possibility that a nongovernmental organization such as a super-consortium of corporations could replace nation-states as the locus of global power.

In the short- and mid-term, a future unipolar system would include both nation-states and non-state actors. There is a sophisticated and large analytical literature that argues that the nation-state, which is essentially an invention of the 17th century, is obsolete and incapable of dealing with modern, transnational problems.[3] In fact, James N. Rosenau notes that the world is already "bifurcated" as nation-states share power with a web of diverse, relatively autonomous non-state actors.[4] Nonetheless, nation-states are likely to persist as an important (if not necessarily the only) element of the international system because of their monopoly on military power and the tradition of nationalism. People are accustomed to paying loyalty to nation-states, and this cannot change overnight. Few if any non-state actors can inspire the extent of support that nation-states can, and no non-state actors can mobilize, train, equip, and sustain a large military. But there is no question that increasing personal mobility, economic interdependence, and global communications will continue to erode traditional notions of sovereignty. The time when a nation such as Mao's China, Stalin's Soviet Union, or Hoxha's Albania could cut itself off from the rest of the world is rapidly passing. Those attempting it, such as North Korea and Myanmar (formerly Burma), will soon pay the price. This means that the importance of non-state actors--whether economic organizations such as cartels, corporations, and consortia, or political ones such as the UN--will also continue to grow.

The principles of a future unipolar system would depend on whether the system is an imperial one, in which the hegemon imposes its power, or a consensual one, in which the smaller units willingly accept the authority and power of the hegemon. If it is an imperial system, history suggests that there would be three guiding principles:

An imperial system can be held together primarily by military force or by cultural and economic interests. The most successful and long-lived empires throughout history have been those initially formed by military force, but then held together by cultural and economic linkages. Examples include the Roman Empire, the Arab/Islamic Empire, the British Empire and Commonwealth, and the various Chinese dynastic empires. Imperial systems forged in war that failed to generate a unifying culture and economy, such as those of Alexander and Genghis Khan, fell apart rapidly. History very strongly suggests that unipolar systems in which consensus-building and diplomacy form the primary currency of relations between the core and periphery are more survivable than those based solely on force. The proliferation of weapons of mass destruction and the evolution of terrorism add to the dangers and burdens of imperial hegemony, and thus make this distinction even more true.

Since there is no exact historic precedent for a consensual unipolar system, the closest analogies are nation-states that emerged from the voluntary unification of smaller units (for example, the United States and Switzerland). Thus it is likely that the guiding principles of a consensual unipolar system would be, first, the power and authority of the central organization grows at the expense of its constituent units, and second, the right of voluntary separation or succession would eventually fade to the point that any such attempts would be met with force.

There are two primary sources of conflict within a unipolar system. The first arises when the hegemon is unable to impose its will in a benign fashion. In all historic unipolar systems, there are Saddam Husseins who underestimate the power or will of the hegemon. If their challenge fails, the system survives; if their rebellion succeeds, the system begins evolving into a bipolar or multipolar configuration. A second type of conflict arises between secondary or peripheral actors when the hegemon is unconcerned. A unipolar system would experience the same sorts of internal conflicts as bipolar or multipolar systems. These could be vertical conflicts between the elite and non-elite (traditional revolution) or horizontal ones pitting ethnic, religious, client, racial, clan, ideological, or political groups. Historically, such internal conflicts challenge the foundation of the international system only if they are very widespread or generate conflict between units, as did the Chinese and Russian revolutions. A major determinant is the hegemon's perspective on internal conflict. If the hegemon considers it a challenge to the system, then it is likely to take steps to contain or quash internal conflict. If the hegemon takes a more benign view of internal conflict at the periphery of the system, it will be widespread. The proliferation of weapons of mass destruction may, however, deny this benign perspective to the hegemon. Even a strictly internal war using them will have immense environmental and humanitarian implications and may very likely provoke outside intervention by the hegemon or with its approval. Phrased differently, it is very unlikely that any sort of effective hegemon could refrain from intervention in a nuclear civil war.

The role of military force in a unipolar system would depend on whether it was consensual or imperial. In an imperial system, military force would remain very important. Military force would be used by the hegemon to retain control and, if the hegemon appears to be in decline, by secondary and peripheral states seeking to reorganize the system. Military force would also be used within states if the hegemon had a high tolerance for internal conflict. In a consensual system or in an imperial one in which the hegemon succeeded in changing from military to cultural or economic forms of control, military force would decline in importance. Its greatest utility would be during the initial consolidation of the system and during its dying days (as at the end of the Chinese, Soviet, Russian, French, or Ottoman empires) when the appeal of secession or autonomy is high.

It is possible to discuss the process of change in a future system in only the broadest terms. Two forces will lead to change in the system and eventually to its downfall. One is a decline in the hegemon's will or ability to rule. For a variety of reasons, hegemons eventually decide that the burdens of empire are greater than the benefits. And, as Paul Kennedy argued, this is sped by the fact that empires tend to rely on military force since that was usually responsible for their ascent to power, and thus ignore their own economic health.[5] At the same time, challengers emulate whatever it was that generated the hegemon's power, and thus power disperses throughout the system. Germany's acquisition in the late 19th century of a navy and empire--the two things considered by Mahan and others to form the cornerstones of British power--was an illustration of this form of emulation. Eventually it helped speed the dissolution of the Eurocentric system.

A second force challenging unipolar systems is the unwillingness of secondary powers to stay in that position. Hegemony is particularly alluring to those who do not have it, thus leading to challenges to the hegemon. Over time, these challenges wear the hegemon down, either spiritually or physically. Along these same lines, it appears that current trends favor the dispersion rather than the concentration of economic power. Wealth is now more information-intensive than production-intensive. The widespread use of microcomputers, facsimile machines, computer assisted design, and cellular communications disperses information where, in the past, large-scale industrialism concentrated wealth. This encourages the dispersion of economic power. During past periods of unipolarity the hegemon parlayed military preponderance into economic, political, and ideological superiority. Any future candidate hegemon would find this difficult to do given the global dispersion of information-based economic power.

In summary, Americans will not allow a non-US dominated unipolar system. World War I, World War II, and the Cold War showed that this is simply unacceptable. But it is equally unlikely that the American public will support an imperial unipolar system or that the rest of the world will tolerate a consensual unipolar system for long. Historically, unipolarity emerged in a regional system when one actor leaped ahead of its contemporaries in the application of power, whether military (the Mongols), political and organizational (the Romans), or psychological/ideological (the Arabs). The communications revolution has made such a leap unlikely. Emulation is simply too easy and too fast. All indicators are, then, that Charles Krauthammer was correct when he suggested that the current unipolarity of the international system is a fleeting aberration.[6]

Bipolar Systems

Americans are certainly comfortable with the notion of bipolarity. A whole generation of strategists and policymakers came of age during the Cold War, and thus views bipolarity as the natural state of the international system. Bipolarity is somewhat more stable and sustainable than unipolarity. If, then, the United States musters the will and the means to remain a superpower and the traditional opposition to unipolarity matures, the post-Cold War system may be bipolar, at least in its initial stages. The key question is: Who or what will be the second superpower? It may be some other nation-state. There are several logical candidates: a revived Russia, an economically dynamic China, a United States of Europe, or a Japan that combines economic power with political ambition and military might. The new superpower might also be a non-state actor. The most likely candidate here would be a greatly strengthened United Nations that had somehow slipped out of the United States' control through changes in structure or procedure.

An even more likely configuration is a bipolar system in which the two opposing superpowers are groupings of nation-states. This would be similar to the Cold War system which pitted the Warsaw Pact against NATO, but the difference would be that the blocs would be less internally hierarchical. Economics could be the criterion for bloc membership. If so, feasible systemic configurations include:

By contrast, the superpowers could also be culturally defined, probably pitting the "West" against the non-West. This is similar to Samuel Huntington's notion that a "clash of civilizations" is replacing the ideological fissures of the Cold War.[7] Ideological conflict could also reemerge, perhaps in the guise of democratic versus non-democratic groupings of states, or even a revived struggle between communism and capitalism.

Both nation-states and non-state actors will be important in any future bipolar system. The relative power of the two will be determined by the degree of conflict in the system and the utility of military force. To the extent the system is conflictual and military force retains a high utility, nation-states will be more important than non-state actors. To the extent that the system is based on cooperative relationships and the peaceful resolution of conflicts, non-state actors such as the United Nations will be more important.

In bipolar systems, there are two alternative sets of principles. Conflictual bipolar systems are based on containment. An example was the pre-détente Cold War system. Each core power in a conflictual bipolar system seeks to expand its influence at the expense of the other. The system, then, is zero-sum, with any gain in power by one superpower automatically considered a loss for the other. Conflict in the system gives military force a high utility for deterrence, enforcement of superpower control over allies and clients, and adjudicating superpower competition in gray areas of the system.

In cooperative bipolar systems the core powers are content with their spheres of influence, do not encourage instability in the other's sphere, and may actually cooperate to preserve order in the periphery. This is a fairly stable arrangement; it was the type of system sought by Nixon and Kissinger during the détente period of the Cold War. In a cooperative bipolar system, military power would decline in utility. Its primary role would be deterrence and a means of preserving intra-bloc order when all other means failed. A cooperative bipolar system would be contingent on some degree of similarity between the two superpowers. It is difficult to conceive of a cooperative bipolar system in which the two core powers are different types of units (geographic nation-state, coalition of states, ideological blocs). If, for example, the United States and a powerful UN were the two superpowers, it would be nearly impossible for them to clearly delineate and respect spheres of influence. It is ironic but true that one of the foundations of the Cold War system was a similarity between the United States and the Soviet Union that was at least as important as the stark distinctions between them. Both were large, heterogeneous nation-states unified by a set of shared values derived from European roots, but at the periphery of the European tradition.[8]

In any bipolar system, conflict arises between units when:

The causes of conflict within units are the same as for the unipolar system: elite/non-elite struggle, and competition between political, ideological, or identity groups.

At the systemic level, change in a bipolar system is usually driven by the weakening of one or both superpowers. Since bipolarity emerges only when there is rough parity between the core powers, this weakening is usually caused by events within the superpower or its bloc, but it can be exacerbated or accelerated by the actions of the other core power, as with the American defense buildup of the 1980s. The weakening can come from military conflict within the bloc, social upheaval, economic decay, or simply a loss of will by the elite. The end of the bipolar conflict in early 17th-century Europe, for example, was due more to the internal problems of Spain than the strategic skill of France. It may lead to the collapse of one superpower and the emergence of a temporary unipolar system or to major war as either the weakening power feels its opportunities are slipping away or the other power sees the chance to destroy its enemy. In ancient Greece, overextension led to Athenian military decline (especially in naval power) and sparked debilitating war among the city-states with Sparta--Athens' rival--the eventual victor. The weakening of a superpower may also lead to the transformation of the bipolar system to a multipolar one as the superpower's control over its bloc fades.

Global trends toward improved communications and transportation, greater personal mobility, and economic interdependence also erode bipolarity. The basis of bipolarity is distinction. Each bloc must define the other as "different." Personal contact and economic exchanges make it difficult to sustain this distinction. This is precisely what happened at the end of the Cold War. It was not only the economic decay of the Soviet Union that led to its collapse, but also the growing openness of that country. It is only a slight overstatement to say that the combination of SDI and CNN brought the end of the Cold War. The same process is now under way in China, although it is economic vibrancy rather than decay that is eroding the old political system. This may suggest that bipolarity itself is an obsolete configuration for the international system.

Multipolar Systems

If frequency of occurrence and long-term survivability are indicators, multipolar systems are the most natural of the three forms. This is primarily due to their flexibility. In a system with three or more core elements, power is diffused and fluid coalitions preserve the system and prevent any one power from dominating it. While all historic multipolar systems have had their share of conflict, they do tend to be better than tight bipolar systems at limiting wars.[10]

The key elements of a future multipolar system would most likely be regions or some other form of supra-state grouping rather than individual nation-states. In terms of the actual composition of the core, the most stable multipolar systems throughout history have been those with five major actors. Given this, the core of a future multipolar system might include:

Note that in this configuration, all except the Islamic world are essentially economic blocs with a clear leader. This would make the Islamic bloc the least stable, and thus the source of much systemic conflict. Other possible (but less likely) members would be economic blocs such as south Asia under the leadership of India, or sub-Saharan Africa under the leadership of South Africa.

If the system were defined primarily by culture, ideology, or, to use Huntington's phrase, civilizations rather than economics, the core might be composed of:

In such a system, the major sources of conflict would not be between the blocs composing the core of the system, but within them. There would invariably be intense competition for leadership within the Islamic bloc (as there has been since the death of the Prophet) and in Asia, while Russia's domination of Eastern Europe would generate persistent problems. Another major source of conflict would be "cusp" states that could belong in more than one bloc, such as Germany, Mexico, and Turkey. The macro-level stability of a multipolar system depends on the internal stability of the blocs composing the core. Core blocs thus often act to preserve order within other core blocs. The United States, United Kingdom, and France, for example, intervened (unsuccessfully) in the Russian Civil War. Outside support to the Austrian emperor during the upheavals of 1848 was more effective. In any future multipolar system, intervention to prop up or stabilize a weak member would be a persistent source of conflict.

The dominant principles of a future multipolar system would vary according to whether it was essentially cooperative or conflictual. In a conflictual system--especially one defined by culture or ideology--conflict would arise from attempts to preserve order within blocs. States would jockey for power within blocs, and the dominant states within a bloc would attempt to prevent disassociation or rebellion by other bloc members--the "Brezhnev Doctrine" would form a general norm. The blocs would be internally homogeneous in ideology, but there would not be a system-wide concept of human rights. Conflict would also occur between blocs, particularly when one is in decline. It was, after all, the decline of the Ottoman Empire that spawned much of the conflict leading to the downfall of the traditional Eurocentric system. A likely principle of such a system, then, would be that the dominant state in a bloc controls external relations. Clearly, military force would play a major role in such a system, and would be used both within a bloc and between blocs.

In a cooperative multipolar system, relations within and between blocs would usually be solved by diplomacy, international law, mediation, or the use of international institutions. Such a system would be inherently more flexible than either unipolar or bipolar systems. Members could move from one bloc to the other. Coalitions of blocs would come and go fairly frequently. Logically, military force would have a relatively limited role in a cooperative multipolar system, and would probably find greater use in preserving internal order within states than in resolving conflicts between them.

In a conflictual multipolar system, military force would be used to:

In a cooperative multipolar system, military force would be used to restrain a renegade or to reinforce the rules of the system.

The energy for change in a multipolar system would come from within the states grouped in blocs. Changes in the various publics' sense of identity would influence foreign policy and cause the coalitions in the system to ebb and flow. A changing sense of identity might cause individual states to move from one bloc to another if blocs are defined by culture or ideology rather than geography. Internal factors might also cause the weakening or strengthening of blocs, which would require the other states in the bloc to take steps either to prop them up or to contain them.

The Role of the United States

In any future international system, the American role will largely be determined by internal factors, especially success or failure at resolving key social conflicts, resuscitating the economy, and rejecting isolationism. This final element is vital. The isolationist tradition runs deep in the American psyche. The activism that began before World War II and continued to the end of the Cold War may prove to be an aberration rather than a sea change in the American strategic tradition. Thus there is always the chance that internal problems will lead us to retreat from the responsibilities of world leadership. Furthermore, failure to craft a coherent post-Cold War national security strategy will exacerbate the isolationist tendency.

What, then, are the specific implications for the US Army of each feasible type of future international system?

Unipolar Systems

Military force would have immense utility in a conflictual unipolar system. The United States would thus need a very large and mobile Army. Given our domestic demographics, this could be sustained only by a draft. Since the United States could find itself fighting relatively well-armed second-tier powers as well as preserving order on the periphery, we would need a wide range of capabilities from ballistic missile defense and conventional warfighting to foreign internal defense. The proliferation of weapons of mass destruction would elevate the importance of counterterrorism for the Army. Most important, a conflictual unipolar system probably would force the Army to undertake sustained garrison and occupation duties in other states. Typically, garrison and occupation troops are drawn either from allies or from second-quality national units. The US Army could thus find itself replicating past imperial armies from ancient Rome to modern Iraq with a clear distinction in quality and mission between first-line and second-line forces. Combined operations would not be significant.

In a cooperative unipolar system the US Army could be much smaller. It would need to retain some conventional warfighting capability to prevent the system from transforming into a bipolar one, and an equal capability for foreign internal defense and other forms of stability-building on the periphery. Unlike the situation in the conflictual unipolar system, the United States could count on allies for more enforcement actions, and thus coalition warfare and combined operations would be more important. Our role would be to provide the type of high technology, high mobility, and special capabilities missing from our allies. Traditional infantry and armor, for example, would be less significant than special operations forces, sophisticated command and control, and advanced air defense. In addition, forward presence would fully replace forward deployment as a key element of our national military strategy. Reconstitution and large-scale mobilization would not be important, so the Total Force concept would have to be redesigned. The reserve component would be focused on domestic rather than warfighting missions.

Bipolar Systems

The Army in a conflictual bipolar system would be similar to that of the Cold War. Basically, it would include two elements. One would be designed to deter, contain, and, if necessary, defeat the other superpower. This would clearly require continuation of the Total Force and demand a reserve component with robust warfighting capability. The other element of the Army would be designed to preserve order within the US bloc, and thus would stress special operations, foreign internal defense, and counterinsurgency. To phrase it differently, the Army would develop distinct high-intensity and low-intensity components. By contrast, the Army would be small and relatively unimportant in a cooperative bipolar system. We would be prepared to lead coalitions in any conflicts that occurred when diplomatic measures failed. The Army would be a highly mobile, high-readiness, but relatively small force serving as the vanguard to coalitions. Support to the UN (or its successor) would probably be significant. From a leadership perspective, the Army would be forced to deal with operations in which the United States is a secondary participant rather than the leader, thus amplifying the importance of assisting allies or friends in the training of competent leaders.

Multipolar Systems

The Army in a conflictual multipolar system also would include two elements--one to deter, fight, and defeat other core powers, and the second designed to preserve order on the periphery. Unlike a bipolar system, a conflictual multipolar system would require the Army to be prepared to fight any one of several potential first-tier enemies, thus demanding greater doctrinal and leadership flexibility. Security assistance would be important, so the Army would need to give special emphasis to all of the various skills attendant to it. Again, the reserve component would need to preserve its warfighting capability. A cooperative multipolar system would require the smallest US Army. Most missions would entail foreign internal defense, with the occasional need to contribute to a coalition of core forces.


The notion of a global system is relatively new. Throughout most of history, the world was composed of a number of disconnected regional balances. It was thus entirely possible to have a unipolar Chinese system, a multipolar Indian system, and a bipolar Mediterranean system coexisting. The world is simply too interconnected for this to occur again. In the future, a given region may be more or less bipolar or multipolar than the global system, but the main global configuration will shape all regional systems to an important degree.

Despite the fact that the nature of the future international system will be a principal determinant of the force structure, doctrine, and missions of the Army, the Army will have only a limited role in shaping the nature of the system. As with demographics, technology, and other factors, the Army is influenced by systemic change rather than controlling or guiding it. What Army strategists must do, then, is remain vigilant for signs that the post-Cold War system is coalescing into one or another of the three broadly stated forms. Indicators of an emerging preference for a particular form could include domestic and international consensus on the guiding principles of the system, especially those concerning the acceptable use of force. Once indicators begin to appear, planners skilled at system-level thinking can begin the task of making the Army an effective organization in whatever configuration the future brings.


1. See Samuel P. Huntington, "The U.S.--Decline or Renewal," Foreign Affairs, 67 (Winter 1988-89), 76-96.

2. See Charles Krauthammer, "The Unipolar Movement," Foreign Affairs, 70 (February 1991), 23-33.

3. The pioneering work in this field was John H. Herz, International Politics in the Atomic Age (New York: Columbia Univ. Press, 1959). Herz felt technology made the nation-state obsolete.

4. James N. Rosenau, Turbulence in World Politics: A Theory of Change and Continuity (Princeton, N.J.: Princeton Univ. Press, 1990).

5. Paul Kennedy, The Rise and Fall of Great Powers: Economic Change and Military Conflict from 1500 to 2000 (New York: Random House, 1987).

6. Krauthammer.

7. Samuel P. Huntington, "The Clash of Civilizations?" Foreign Affairs, 72 (Summer 1993), 22-49.

8. Alexis de Tocqueville first noted this similarity in the mid-19th century.

9. The standard work on this notion is Robert Jervis, Perception and Misperception in International Politics (Princeton, N.J.: Princeton Univ. Press, 1976).

10. Karl W. Deutsch and J. David Singer, "Multipolar Power Systems and International Stability," in International Politics and Foreign Policy, ed. James N. Rosenau (New York: Free Press, 1969), pp. 315-24. 

Dr. Steven Metz is associate research professor of national security affairs at the Strategic Studies Institute, US Army War College. He holds B.A. and M.A. degrees in international studies from the University of South Carolina and a Ph.D. in political science from Johns Hopkins University. Dr. Metz has served on the faculty at the Air War College, US Army Command and General Staff College, and several universities. He also has been an adviser to political organizations and campaigns. He is the author of Eisenhower as Strategist: The Coherent Use of Military Power in War and Peace and many articles on national security policy, military strategy, and world politics.

Reviewed 29 August 1997. Please send comments or corrections to