The Origins of War in Neorealist Theory
Author(s): Kenneth N. Waltz
Source: The Journal of Interdisciplinary History , Spring, 1988, Vol. 18, No. 4, The
Origin and Prevention of Major Wars (Spring, 1988), pp. 615-628
Published by: The MIT Press
Stable URL: https://www.jstor.org/stable/204817
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Journal of Interdisciplinary History, xvIII:4 (Spring 1988), 615-628.
Kenneth N. Waltz
The Origins of War in Neorealist Theory Like
most historians, many students of international politics have been
skeptical about the possibility of creating a theory that might help
one to understand and explain the international events that interest
us. Thus Morgenthau, foremost among traditional realists, was
fond of repeating Blaise Pascal's remark that "the history of the
world would have been different had Cleopatra's nose been a bit
shorter" and then asking "How do you systemize that?"1 His
appreciation of the role of the accidental and the occurrence of
the unexpected in politics dampened his theoretical ambition.
The response of neorealists is that, although difficulties
abound, some of the obstacles that seem most daunting lie in
misapprehensions about theory. Theory obviously cannot explain
the accidental or account for unexpected events; it deals in regularities
and repetitions and is possible only if these can be identified.
A further difficulty is found in the failure of realists to
conceive of international politics as a distinct domain about which
theories can be fashioned. Morgenthau, for example, insisted on
"the autonomy of politics," but he failed to apply the concept to
international politics. A theory is a depiction of the organization
of a domain and of the connections among its parts. A theory
indicates that some factors are more important than others and
specifies relations among them. In reality, everything is related to
everything else, and one domain cannot be separated from others.
But theory isolates one realm from all others in order to deal with
it intellectually. By defining the structure of international political
Kenneth N. Waltz is Ford Professor of Political Science at the University of California,
Berkeley. He is the author of The Spread of Nuclear Weapons (London, 1981). He is currently
the President of the American Political Science Association.
The author thanks David Schleicher, who was most helpful in the completion of this
article.
? I988 by The Massachusetts Institute of Technology and the editors of The Journal of
Interdisciplinary History.
I Hans J. Morgenthau, "International Relations: Quantitative and Qualitative Approaches,"
in Norman D. Palmer (ed.), A Design for International Relations Research: Scope,
Theory, Methods, and Relevance (Philadelphia, 1970), 78.
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616 KENNETH N. WALTZ
systems, neorealism establishes the autonomy of intern
itics and thus makes a theory about it possible.2
In developing a theory of international politics,
retains the main tenets of realpolitik, but means an
viewed differently, as are causes and effects. Morg
example, thought of the "rational" statesman as ever
accumulate more and more power. He viewed pow
in itself. Although he acknowledged that nations at
of considerations other than power, Morgenthau in
when they do so, their actions are not "of a political
contrast, neorealism sees power as a possibly useful m
states running risks if they have either too little or
it. Excessive weakness may invite an attack that grea
would have dissuaded an adversary from launchin
strength may prompt other states to increase their a
their efforts against the dominant state. Because pow
sibly useful means, sensible statesmen try to have an
amount of it. In crucial situations, however, the ultim
of states is not for power but for security. This re
important one.
An even more important revision is found in a shift
relations. The infinite materials of any realm can be
endlessly different ways. Realism thinks of causes
only one direction, from the interactions of individu
to the outcomes that their acts and interactions pro
genthau recognized that, when there is competition
goods and no one to serve as arbiter, a struggle for
ensue among the competitors and that consequently
for power can be explained without reference to the
men. The struggle for power arises simply becaus
things, not because of the evil in their desires. He l
desire for scarce goods as one of the two roots of co
even while discussing it, he seemed to pull toward th
2 Morgenthau, Politics among Nations (New York, 1973; 5th ed.), I . Lu
(trans. Rudolf Weingartner), "Theories as Representations," excerpted i
and Sidney Morgenbesser (eds.), Philosophy of Science (Cleveland, 1960
realism is sometimes dubbed structural realism. I use the terms interc
throughout this article, refer to my own formulation of neorealist th
Theory of International Politics (Reading, Mass., I979); Robert Keohane
and its Critics (New York, I986).
3 Morgenthau, Politics among Nations, 27.
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WAR IN NEOREALIST THEORY 617
of conflict and concomitant evil"-"the animus dominandi, the desire
for power." He often considered that man's drive for power
is more basic than the chance conditions under which struggles
for power occur. This attitude is seen in his statement that "in a
world where power counts, no nation pursuing a rational policy
has a choice between renouncing and wanting power; and, if it
could, the lust for power for the individual's sake would still
confront us with its less spectacular yet no less pressing moral
defects. "4
Students of international politics have typically inferred outcomes
from salient attributes of the actors producing them. Thus
Marxists, like liberals, have linked the outbreak of war or the
prevalence of peace to the internal qualities of states. Governmental
forms, economic systems, social institutions, political
ideologies-these are but a few examples of where the causes of
war have been found. Yet, although causes are specifically assigned,
we know that states with widely divergent economic
institutions, social customs, and political ideologies have all
fought wars. More striking still, many different sorts of organizations
fight wars, whether those organizations be tribes, petty
principalities, empires, nations, or street gangs. If an identified
condition seems to have caused a given war, one must wonder
why wars occur repeatedly even though their causes vary. Variations
in the characteristics of the states are not linked directly to
the outcomes that their behaviors produce, nor are variations in
their patterns of interaction. Many historians, for example, have
claimed that World War I was caused by the interaction of two
opposed and closely balanced coalitions. But then many have
claimed that World War II was caused by the failure of some states
to combine forces in an effort to right an imbalance of power
created by an existing alliance.
Neorealism contends that international politics can be understood
only if the effects of structure are added to the unit-level
explanations of traditional realism. By emphasizing how structures
affect actions and outcomes, neorealism rejects the assumption
that man's innate lust for power constitutes a sufficient cause
of war in the absence of any other. It reconceives the causal link
between interacting units and international outcomes. According
4 Idem, Scientific Man vs. Power Politics (Chicago, I946), 192, 200. Italics added.
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6I8 KENNETH N. WALTZ
to the logic of international politics, one must bel
causes of international outcomes are the result of interactions at
the unit level, and, since variations in presumed causes do not
correspond very closely to variations in observed outcomes, one
must also assume that others are located at the structural level.
Causes at the level of units interact with those at the level of
structure, and, because they do so, explanation at the unit level
alone is bound to be misleading. If an approach allows the consideration
of both unit-level and structural-level causes, then it
can cope with both the changes and the continuities that occur in
a system.
Structural realism presents a systemic portrait of international
politics depicting component units according to the manner of
their arrangement. For the purpose of developing a theory, states
are cast as unitary actors wanting at least to survive, and are taken
to be the system's constituent units. The essential structural quality
of the system is anarchy-the absence of a central monopoly
of legitimate force. Changes of structure and hence of system
occur with variations in the number of great powers. The range
of expected outcomes is inferred from the assumed motivation of
the units and the structure of the system in which they act.
A systems theory of international politics deals with forces
at the international, and not at the national, level. With both
systems-level and unit-level forces in play, how can one construct
a theory of international politics without simultaneously constructing
a theory of foreign policy? An international-political
theory does not imply or require a theory of foreign policy any
more than a market theory implies or requires a theory of the
firm. Systems theories, whether political or economic, are theories
that explain how the organization of a realm acts as a constraining
and disposing force on the interacting units within it.
Such theories tell us about the forces to which the units are
subjected. From them, we can draw some inferences about the
expected behavior and fate of the units: namely, how they will
have to compete with and adjust to one another if they are to
survive and flourish. To the extent that the dynamics of a system
limit the freedom of its units, their behavior and the outcomes of
their behavior become predictable. How do we expect firms to
respond to differently structured markets, and states to differently
structured international-political systems? These theoretical quesThis
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WAR IN NEOREALIST THEORY 619
tions require us to take firms as firms, and states as states, withou
paying attention to differences among them. The questions ar
then answered by reference to the placement of the units in their
system and not by reference to the internal qualities of the units.
Systems theories explain why different units behave similarly and,
despite their variations, produce outcomes that fall within expected
ranges. Conversely, theories at the unit level tell us wh
different units behave differently despite their similar placement
in a system. A theory about foreign policy is a theory at th
national level. It leads to expectations about the responses that
dissimilar polities will make to external pressures. A theory of
international politics bears on the foreign policies of nations although
it claims to explain only certain aspects of them. It ca
tell us what international conditions national policies have to cop
with.
From the vantage point of neorealist theory, competition an
conflict among states stem directly from the twin facts of lif
under conditions of anarchy: States in an anarchic order must
provide for their own security, and threats or seeming threats t
their security abound. Preoccupation with identifying dangers and
counteracting them become a way of life. Relations remain tens
the actors are usually suspicious and often hostile even though b
nature they may not be given to suspicion and hostility. Individ
ually, states may only be doing what they can to bolster their
security. Their individual intentions aside, collectively their ac
tions yield arms races and alliances. The uneasy state of affairs i
exacerbated by the familiar "security dilemma," wherein measur
that enhance one state's security typically diminish that of others.5
In an anarchic domain, the source of one's own comfort is the
source of another's worry. Hence a state that is amassing instru
ments of war, even for its own defensive, is cast by others as a
threat requiring response. The response itself then serves to con
firm the first state's belief that it had reason to worry. Similar
an alliance that in the interest of defense moves to increase cohesion
among its members and add to its ranks inadvertently imperils
an opposing alliance and provokes countermeasures.
Some states may hunger for power for power's sake. Neorealist
theory, however, shows that it is not necessary to assume
5 See John H. Herz, "Idealist Internationalism and the Security Dilemma," World Politics,
II (I950), I57-I80.
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620 KENNETH N. WALTZ
an innate lust for power in order to account for th
fierce competition that marks the international aren
archic domain, a state of war exists if all parties lus
But so too will a state of war exist if all states seek o
their own safety.
Although neorealist theory does not explain why
wars are fought, it does explain war's dismal recurre
the millennia. Neorealists point not to the ambition
trigues that punctuate the outbreak of individual c
instead to the existing structure within which events, w
design or accident, can precipitate open clashes o
origins of hot wars lie in cold wars, and the origins
are found in the anarchic ordering of the internation
The recurrence of war is explained by the struct
international system. Theorists explain what histor
War is normal. Any given war is explained not by lo
structure of the international-political system but b
the particularities within it: the situations, the characte
interactions of states. Although particular explanatio
at the unit level, general explanations are also needed
in frequency, and in other ways as well. A central qu
structural theory is this: How do changes of the system
expected frequency of war?
KEEPING WARS COLD: THE STRUCTURAL LEVEL In an anarchic
realm, peace is fragile. The prolongation of peace requires tha
potentially destabilizing developments elicit the interest and th
calculated response of some or all of the system's principal actor
In the anarchy of states, the price of inattention or miscalculation
is often paid in blood. An important issue for a structural theor
to address is whether destabilizing conditions and events are ma
aged better in multipolar or bipolar systems.
In a system of, say, five great powers, the politics of powe
turns on the diplomacy by which alliances are made, maintaine
and disrupted. Flexibility of alignment means both that the cou
try one is wooing may prefer another suitor and that one's present
alliance partner may defect. Flexibility of alignment limits a state'
options because, ideally, its strategy must please potential alli
and satisfy present partners. Alliances are made by states that have
some but not all of their interests in common. The common
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WAR IN NEOREALIST THEORY 621
interest is ordinarily a negative one: fear of other s
gence comes when positive interests are at issue
among near equals, strategies are always the product
mise since the interests of allies and their notions of how to secure
them are never identical.
If competing blocs are seen to be closely balanced, and if
competition turns on important matters, then to let one's side
down risks one's own destruction. In a moment of crisis the
weaker or the more adventurous party is likely to determin
side's policy. Its partners can afford neither to let the weak
member be defeated nor to advertise their disunity by failin
back a venture even while deploring its risks.
The prelude to World War I provides striking examples
such a situation. The approximate equality of partners in both
Triple Alliance and Triple Entente made them closely interde
dent. This interdependence, combined with the keen compet
between the two camps, meant that, although any country c
commit its associates, no one country on either side could exe
control. If Austria-Hungary marched, Germany had to foll
the dissolution of the Austro-Hungarian Empire would have
Germany alone in the middle of Europe. If France marc
Russia had to follow; a German victory over France would b
defeat for Russia. And so the vicious circle continued. Because
the defeat or the defection of a major ally would have shaken
balance, each state was constrained to adjust its strategy and t
use of its forces to the aims and fears of its partners.
In alliances among equals, the defection of one membe
threatens the security of the others. In alliances among unequa
the contributions of the lesser members are at once wanted and
of relatively small importance. In alliances among unequals, alli
ance leaders need worry little about the faithfulness of their fol
lowers, who usually have little choice anyway. Contrast the sit
uation in I914 with that of the United States and Britain and
France in I956. The United States could dissociate itself from the
Suez adventure of its two principal allies and subject one of them
to heavy financial pressure. Like Austria-Hungary in 1914, Britain
and France tried to commit or at least immobilize their ally by
presenting a fait accompli. Enjoying a position of predominance,
the United States could continue to focus its attention on the
major adversary while disciplining its two allies. Opposing Br
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622 KENNETH N. WALTZ
ain and France endangered neither the United State
ance because the security of Britain and France de
more heavily on us than our security depended
ability of the United States, and the inability of Ge
a price measured in intra-alliance terms is striking.
In balance-of-power politics old style, flexibility of
led to rigidity of strategy or the limitation of freedo
In balance-of-power politics new style, the obvers
idity of alignment in a two-power world results in m
of strategy and greater freedom of decision. In a mul
roughly equal parties engaged in cooperative endeav
for the common denominator of their policies. The
the lowest one and easily end up in the worst o
worlds. In a bipolar world, alliance leaders can des
primarily to advance their own interests and to co
main adversary and less to satisfy their own allies.
Neither the United States nor the Soviet Union has to seek
the approval of other states, but each has to cope with the othe
In the great-power politics of a multipolar world, who is a dang
to whom and who can be expected to deal with threats an
problems are matters of uncertainty. In the great-power politi
of a bipolar world, who is a danger to whom is never in doubt
Any event in the world that involves the fortunes of either of the
great powers automatically elicits the interest of the other. Pre
ident Harry S. Truman, at the time of the Korean invasion, coul
not very well echo Neville Chamberlain's words in the Czechoslovakian
crisis by claiming that the Americans knew nothing
about the Koreans, a people living far away in the east of Asia
We had to know about them or quickly find out.
In a two-power competition, a loss for one is easily taken to
be a gain for the other. As a result, the powers in a bipolar wor
promptly respond to unsettling events. In a multipolar world,
dangers are diffused, responsibilities unclear, and definitions
vital interests easily obscured. Where a number of states are i
balance, the skillful foreign policy of a forward power is design
to gain an advantage without antagonizing other states and frightening
them into united action. At times in modern Europe, th
benefits of possible gains have seemed to outweigh the risks o
likely losses. Statesmen have hoped to push an issue to the lim
without causing all of the potential opponents to unite. When
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WAR IN NEOREALIST THEORY | 623
there are several possible enemies, unity of action among them is
difficult to achieve. National leaders could therefore think-or
desperately hope, as did Theobald von Bethmann Hollweg a
Adolf Hitler before two world wars-that a united oppositi
would not form.
If interests and ambitions conflict, the absence of crises is
more worrisome than their presence. Crises are produced by the
determination of a state to resist a change that another state tries
to make. As the leaders in a bipolar system, the United States
and the Soviet Union are disposed to do the resisting, for in
important matters they cannot hope that their allies will do it for
them. Political action in the postwar world has reflected this
condition. Communist guerrillas operating in Greece prompted
the Truman Doctrine. The tightening of Soviet control over the
states of Eastern Europe led to the Marshall Plan and the Atlantic
Defense Treaty, and these in turn gave rise to the Cominform
and the Warsaw Pact. The plan to create a West German government
produced the Berlin blockade. During the past four decades,
our responses have been geared to the Soviet Union's actions,
and theirs to ours.
Miscalculation by some or all of the great powers is a source
of danger in a multipolar world; overreaction by either or both
of the great powers is a source of danger in a bipolar world.
Which is worse: miscalculation or overreaction? Miscalculation is
the greater evil because it is more likely to permit an unfolding
of events that finally threatens the status quo and brings the
powers to war. Overreaction is the lesser evil because at worst it
costs only money for unnecessary arms and possibly the fighting
of limited wars. The dynamics of a bipolar system, moreover,
provide a measure of correction. In a world in which two states
united in their mutual antagonism overshadow any others, the
benefits of a calculated response stand out most clearly, and the
sanctions against irresponsible behavior achieve their greatest
force. Thus two states, isolationist by tradition, untutored in the
ways of international politics, and famed for impulsive behavior,
have shown themselves-not always and everywhere, but always
in crucial cases-to be wary, alert, cautious, flexible, and for-
bearing.
Moreover, the economies of the great powers in a bipolar
world are less interdependent than those of the great powers of a
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624 KENNETH N. WALTZ
multipolar one. The size of great powers tends to incr
numbers fall, and the larger a state is, the greater th
its resources. States of continental size do proportion
their business abroad than, for example, Britain,
Germany did in their heydays. Never before in mod
have the great powers depended so little on the out
and been so uninvolved in one another's economic affairs, as the
United States and the Soviet Union have been since the war. The
separation of their interests reduces the occasions for dispute an
permits them, if they wish, to leave each other alone even thoug
each defines its security interests largely in terms of the other.
Interdependence of parties, diffusion of dangers, confusion
of responses: These are the characteristics of great-power politic
in a multipolar world. Self-dependence of parties, clarity of dan
gers, certainty about who has to face them: These are the char
acteristics of great-power politics in a bipolar world.
KEEPING WARS COLD: THE UNIT LEVEL A major reason for th
prolongation of the postwar peace is the destruction of the old
multipolar world in World War II and its replacement by a bipola
one. In a bipolar world, we expect competition to be keen, yet
manageable. But to believe that bipolarity alone accounts for the
"long peace" between the United States and the Soviet Union is
difficult. Given the depth and extent of the distrust felt by bot
parties, one may easily believe that one or another of the crise
that they have experienced would, in earlier times, have drawn
them into war. For a fuller explanation of why that did no
happen, we must look to that other great force for peace: nuclea
weapons.
States continue to coexist in an anarchic order. Self-help is
the principle of action in such an order, and the most importan
way in which states must help themselves is by providing for
their own security. Therefore, in weighing the chances of peac
the first questions to ask are questions about the ends for whic
states use force and about the strategies and weapons they employ.
The chances of peace rise if states can achieve their most important
ends without actively using force. War becomes less likely as th
costs of war rise in relation to the possible gains. Realist theory
old and new alike, draws attention to the crucial role of militar
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WAR IN NEOREALIST THEORY 625
technology and strategy among the forces that fix the fate of state
and their systems.
Nuclear weapons dissuade states from going to war much
more surely than conventional weapons do. In a convention
world, states can believe both that they may win and that, shou
they lose, the price of defeat will be bearable, although World
Wars I and II called the latter belief into question even before
atomic bombs were dropped. If the United States and the Sovie
Union were now armed only with conventional weapons, th
lessons of those wars would be clearly remembered, especially b
the Soviet Union, which suffered more in war than the United
States. Had the atom never been split, those two nations would
still have much to fear from each other. Armed with increasingl
destructive conventional weapons, they would be constrained t
strive earnestly to avoid war. Yet, in a conventional world, even
sad and strong lessons like those of the two world wars hav
proved exceedingly difficult for states to learn. Throughout mod
ern history, one great power or another has looked as though it
might become dangerously strong: for example, France under
Louis XIV and Napoleon Bonaparte, and Germany under Wi
helm II and Hitler. In each case, an opposing coalition forme
and turned the expansive state back. The lessons of history woul
seem to be clear: In international politics, success leads to failure
The excessive accumulation of power by one state or coalition
states elicits the opposition of others. The leaders of expansioni
states have nevertheless been able to persuade themselves that
skillful diplomacy and clever strategy would enable them to tran
scend the normal processes of balance-of-power politics.
The experience of World War II, bipolarity, and the increased
destructiveness of conventional weapons would make World War
III more difficult to start than earlier wars were; and the presence
of nuclear weapons dramatically increases that difficulty. Nuclea
weapons reverse or negate many of the conventional causes of
war. Wars can be fought in the face of nuclear weapons, but th
higher the stakes and the closer a country comes to winning them,
the more surely that country invites retaliation and risks its ow
destruction. The accumulation of significant power through con
quest, even if only conventional weapons are used, is no longer
possible in the world of nuclear powers. Those individuals who
believe that the Soviet Union's leaders are so bent on world
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626 KENNETH N. WALTZ
domination that they may be willing to run catastrop
problematic gains fail to understand how governm
Do we expect to lose one city or two? Two cities o
these are the pertinent questions, political leaders s
about running risks and start worrying about how
Deterrence is more easily achieved than most m
egists would have us believe. In a conventional wor
can sensibly attack if it believes that success is
nuclear world, a country cannot sensibly attack un
that success is assured. A nation will be deterred fr
even if it believes that there is only a possibility that
will retaliate. Uncertainty of response, not certain
for deterrence because, if retaliation occurs, one ri
As Clausewitz wrote: If war approaches the absolu
imperative "not to take the first step without think
be the last."6
Nuclear weapons make the implications even of victory too
horrible to contemplate. The problem that the nuclear powers
must solve is how to perpetuate peace when it is not possible to
eliminate all of the causes of war. The structure of international
politics has not been transformed; it remains anarchic in form.
Nuclear states continue to compete militarily. With each state
striving to ensure its own security, war remains constantly possible.
In the anarchy of states, improving the means of defense
and deterrence relative to the means of offense increases the
chances of peace. Weapons and strategies that make defense
deterrence easier, and offensive strikes harder to mount, decr
the likelihood of war.7
Although the possibility of war remains, the probability of
a war involving states with nuclear weapons has been drastically
reduced. Over the centuries great powers have fought more wars
than minor states, and the frequency of war has correlated more
closely with a structural characteristic-their international standing-than
with unit-level attributes. Yet, because of a change in
military technology, a change at the unit level, waging war has
6 Karl von Clausewitz (ed. Anatol Rapaport; trans. J. J. Graham), On War (Hammondsworth,
I968), V, 374.
7 See Malcolm W. Hoag, "On Stability in Deterrent Races," in Morton A. Kaplan (ed.),
The Revolution in World Politics (New York, 1962), 388-4IO; Robert Jervis, "Cooperation
under the Security Dilemma," World Politics, XXX (I978), I67-214.
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WAR IN NEOREALIST THEORY | 627
increasingly become the privilege of poor and weak states. Nuclear
weapons have banished war from the center of international
politics. A unit-level change has dramatically reduced a structural
effect.
The probability of major war among states having nuclear
weapons approaches zero. But the "real war" may, as James
claimed, lie in the preparations for waging it. The logic of a
deterrent strategy, if it is followed, also circumscribes the causes
of "real wars."8 In a conventional world, the structure of international
politics encourages states to arm competitively. In a nuclear
world, deterrent strategies offer the possibility of dampening
the competition. Conventional weapons are relative. With conventionl
weapons, competing countries must constantly compare
their strengths. How secure a country is depends on how it
compares to others in the quantity and quality of its weaponry,
the suitability of its strategy, the resilience of its society and
economy, and the skill of its leaders.
Nuclear weapons are not relative but absolute weapons.9
They make it possible for a state to limit the size of its strategic
forces so long as other states are unable to achieve disarming firststrike
capabilities by improving their forces. If no state can launch
a disarming attack with high confidence, comparing the size of
strategic forces becomes irrelevant. For deterrence, one asks how
much is enough, and enough is defined as a second-strike capability.
This interpretation does not imply that a deterrent force
can deter everything, but rather that, beyond a certain level,
additional forces provide no additional security for one party and
pose no additional threat to others. The two principal powers in
the system have long had second-strike forces, with neither able
to launch a disarming strike against the other. That both nevertheless
continue to pile weapon upon unneeded weapon is a puzzle
whose solution can be found only within the United States and
the Soviet Union.
WARS, HOT AND COLD Wars, hot and cold, originate in the
structure of the international political system. Most Americans
8 William James, "The Moral Equivalent of War," in Leon Bramson and George W.
Goethals (eds.), War: Studiesfrom Psychology, Sociology, and Anthropology (New York, I968;
rev. ed.), 23.
9 Cf. Bernard Brodie, The Absolute Weapon: Atomic Power and World Order (New York,
1946), 75-76.
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628 KENNETH N. WALTZ
blame the Soviet Union for creating the Cold War,
that follow necessarily from the nature of its socie
ment. Revisionist historians, attacking the dominan
blame to the United States. Some American error, or sinister
interest, or faulty assumption about Soviet aims, they argue, is
what started the Cold War. Either way, the main point is lost. In
a bipolar world, each of the two great powers is bound to focus
its fears on the other, to distrust its motives, and to impute
offensive intentions to defensive measures. The proper question
is what, not who, started the Cold War. Although its content and
virulence vary as unit-level forces change and interact, the Cold
War continues. It is firmly rooted in the structure of postwar
international politics, and will last as long as that structure en-
dures.
In any closely competitive system, it may seem that one is
either paranoid or a loser. The many Americans who ascribe
paranoia to the Soviet Union are saying little about its political
elite and much about the international-political system. Yet, in
the presence of nuclear weapons, the Cold War has not become
a hot one, a raging war among major states. Constraints on
fighting big wars have bound the major nuclear states into a
system of uneasy peace. Hot wars originate in the structure of
international politics. So does the Cold War, with its temperature
kept low by the presence of nuclear weapons.
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