Seminar III. Lecture 8.
Nuclear War and Limited War
By
Antulio Echevarria, Ph.D.
U.S. Army War College
“The atom’s power . . . can be used as an overriding influence against aggression and
reckless war.”
Harry S. Truman, 1946
At first glance, President Harry Truman’s opinion, voiced in 1946, seem to reflect more
optimism than realism. That itself should not be surprising. After all, they came just
after the Second World War, when the United States stood alone as an atomic power, and
could destroy a reckless aggressor with impunity. Indeed, this was the basis of President
Eisenhower’s later policy of massive retaliation.
However, as Henry Kissinger
subsequently remarked in his influential book, The Necessity for Choice (1962), and
Truman probably well understood even in 1946, atomic or nuclear weapons were not
sufficient grounds for deterring aggression, nor were they even a sound basis for national
strategy. 1 They might deter a massive invasion of one’s homeland in most cases, but to
use them against a belligerent in a localized, limited conflict seemed utterly
disproportionate, even immoral. Unless a belligerent believes a particular weapon will be
used against him, it has no deterrent value. In other words, if escalation to nuclear war is
a state’s only option, but the majority of contemporary scenarios do not justify the use of
that option, that state is essentially helpless strategically. Its nuclear arsenal becomes an
expensive paper tiger.
Clearly, another military option was needed to complement
weapons of mass destruction. A number of American strategists during the Cold War
saw limited war as that option.
This lesson introduces the student of military thought to the basic premises underpinning
the leading theories of nuclear war, nuclear deterrence, and limited war.
1
Henry A. Kissinger, The Necessity for Choice: Prospects of American Foreign Policy (New York:
Doubleday, 1962), 61.
Lesson 8, 2
Nuclear War and Nuclear Deterrence
Whereas in 1946 Truman believed (or perhaps hoped is more accurate) that the threat of
atomic weapons might dissuade recourse to armed conflict, many strategists and theorists
took a different view. In essence, they set aside the widely held belief that a nuclear war
would be prohibitively destructive, and attempted to “think the unthinkable.” Their
starting premise was that nuclear wars were not necessarily unwinnable, and, thus, efforts
to prevent them might be reactionary. By the mid-1950s, articles had already appeared in
defense journals discussing how nuclear wars might, in fact, be carried out. Trigger lines,
target priorities, and kill ratios were all discussed, as well as the necessity for mapping
out responses in advance.
The leading theorist of the “unthinkable” school of thought was the physicist Herman
Kahn (1922-1983), who believed the United States actually could prevail in a nuclear
exchange with the Soviet Union.
He was credited with having the highest IQ in
American history at the time, and his massive tome, On Thermonuclear War (a deliberate
play on Clausewitz’s On War), published in 1960, almost proved it. 2
The greatest
obstacle to the use of nuclear weapons, Kahn seemed to say, was our inability to conceive
it objectively. If strategists could overcome their mental blocks, and look at the facts, at
least those Kahn presented, they might see situations in which the use of nuclear weapons
was appropriate, and controllable.
While a nuclear war would surely be devastating, Kahn maintained that life in some form
would go on, just as it had after some of history’s more catastrophic wars and natural
disasters. He stressed that there were numerous situations in which a nuclear exchange
might occur, and yet not lead to global destruction. For instance, he envisioned a
“limited” nuclear war scenario in which tit-for-tat nuclear exchanges took place between
two superpowers, each destroying the other’s cities one-by-one until a peace settlement
was reached.
2
Herman Kahn, On Thermonuclear War (Princeton: Princeton University, 1960).
Lesson 8, 3
In 1965, Kahn published On Escalation, which explored the concept of escalation, a term
he may well have coined. 3 Certainly, he provided the first “scientific” analysis of the
concept. In Kahn’s view, escalation was not necessarily to be avoided. In fact, it could
be used to coerce an opponent into complying with one’s demands. Kahn observed that
ratcheting up, or escalating, the pain or cost level of certain activities could dissuade
states from pursuing them. He developed a detailed, 44-step escalation ladder, which laid
out six psychological thresholds covering the entire spectrum of war (see Figure 1).
Interestingly, Kahn presents nine levels of escalation that could occur before the use of
nuclear weapons even becomes a concern for the powers involved. There are ten more
levels of escalation before nuclear weapons are actually used. In other words, almost half
of Kahn’s levels of escalation could occur before the “nuclear threshold” is even crossed.
Put differently, a little more than half of the levels of escalation could occur after the first
nuclear weapon is used, leaving a broad array of possibilities for nuclear war short of
mutual annihilation. How quickly escalation might occur from any step to another, is of
course impossible to say. The last step, Spasm or Insensate War, describes a level where
states continue to launch their weapons after their major cities and command and control
centers are destroyed, like a spider whose legs keep flinching long after it is dead. It is
certainly possible that this step could be reached within hours, or minutes, of crossing the
nuclear threshold, and that many of the intervening steps might, in fact, simply be
bypassed.
3
Herman Kahn, On Escalation (New York: Praeger, 1965).
Lesson 8, 4
Fig. 1. AN ESCALATION LADDER by Herman Khan
A Generalized (or Abstract) Scenario
AFTERMATHS
Civilian
Central
Wars
Military
Central
Wars
Exemplary
Central
Attacks
Bizarre
Crises
Intense
Crises
Traditional
Crises
Sub-crisis
Maneuvering
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Spasm or Insensate War
Some Other Kinds of Controlled General War
Civilian Devastation Attack
Augmented Disarming Attack
Counter-value Salvo
Slow-Motion Counter-city War
(CITY TARGETING THRESHOLD)
Unmodified Counterforce Attack
Counterforce-With-Avoidance Attack
Constrained Disarming Attack
Constrained Force-Reduction Salvo
Slow-Motion Counterforce War
Slow-Motion Counter – “Property” War
Formal Declaration of “General” War
(CENTRAL WAR THRESHOLD)
Reciprocal Reprisals
Complete Evacuation (Approximately 95 per cent)
Exemplary Attacks against Population
Exemplary Attacks against Property
Exemplary Attacks on Military
Demonstration Attacks on Zone of Interior
(CENTRAL SANCTUARY THRESHOLD)
Evacuation (Approximately 70 per cent)
Unusual, Provocative, and Significant Countermeasures
Local Nuclear War – Military
Declaration of Limited Nuclear War
Local Nuclear War – Exemplary
(NO NUCLEAR USE THRESHOLD)
“Peaceful” World-Wide Embargo or Blockade
“Justifiable” Counterforce Attack
Spectacular Show or Demonstration of Force
Limited Evacuation (Approximately 20 per cent)
Nuclear “Ultimatums”
Barely Nuclear War
Declaration of Limited Conventional War
Large Compound Escalation
Large Conventional War (Or Action)
Super-Ready Status
Provocative Breaking Off of Diplomatic Relations
(NUCLEAR WAR IS UNTHINKABLE THRESHOLD)
Dramatic Military Confrontations
Harassing Acts of Violence
“Legal” Harassment – Retorts
Significant Mobilization
Show of Force
Hardening of Positions – Confrontations of Wills
(DON'T ROCK THE BOAT THRESHOLD)
Solemn and Formal Declarations
Political, Economic, and Diplomatic Gestures
Ostensible Crisis
DISAGREEMENT — COLD WAR
Lesson 8, 5
In a positive sense, Kahn’s ladder gave decision makers a framework from which to
consider the urgency of particular kinds of belligerent acts. In another, somewhat more
dangerous sense, however, it seemed to lay down a set of rules or guidelines concerning
how certain acts ought to be viewed, and how statesmen should respond to them. The
problem with such an approach, of course, is that one’s opponent may not be working
from the same framework, which could lead to egregious choices. Also, in following any
framework, one’s actions tend to become not only predictable, but prescribed.
In the final analysis, Kahn’s ladder is more applicable to the realm of game theory, where
abstract scenarios are studied and war-gamed for a variety of research-related reasons,
rather than to the world of international relations where the fog of misunderstanding is
often thick and persistent.
Although “thinking the unthinkable” was perhaps a necessary evil at the time, Kahn’s
works were, in all, simply too clever by half. Critics condemned his approach, and
rightly, for treating nuclear war as an end in itself. His works were long on tables and
figures, but short on analyses of how nuclear exchanges might serve real rather than
abstract policy aims. It is important to keep in mind that Kahn and most of those in his
school of thought had virtually no combat or diplomatic experience. Their concepts and
their nuclear-use jargon were developed through some rather insular processes, with all
the potential for error such processes entail.
Whereas Kahn had hoped to supplant Clausewitz’s On War with his own more modern
treatment, his critics—among them Bernard Brodie, Michael Howard, Peter Paret, and
Raymond Aron—came to the Prussian’s defense. By stressing Clausewitz’s apparent
dictum regarding the subordination of war to policy, they simultaneously and deftly
undercut Kahn’s argument, and those of his advocates. Policy must remain preeminent in
war and strategy, they maintained, lest war itself escalate out of control.
Although this was not precisely Clausewitz’s argument, it was close enough for many
scholars, particularly for strategic theorists such as Brodie, who did a masterful job of
expounding upon it in his opus, War and Politics (1973). Clausewitz’s actual point, as
the student will note from reading Chapter 1 of Book I, was that war does not escalate of
its own accord; rather, it is a combination of policy and politics—meaning the larger
Lesson 8, 6
political context within which decisions are made by those in charge—which prompt war
to escalate or de-escalate. Put differently, in Clausewitz’s view, there was nothing
intrinsic to war that would cause it to escalate. Instead, it is what goes on in the heads of
statesmen and generals that causes the level and type of violence to change. Statesmen
whose heads were full of the ideas of Kahn were, in the ideas of Brodie and others,
dangerously wrong. From Kahn’s perspective, in contrast, political leaders whose heads
were full of Brodie-like angst were unnecessarily timid.
Deterrence and Nuclear Deterrence
In 1946, the same year that President Truman expressed his hope about the power of the
atom, Brodie advanced the view that atomic weapons had brought about a revolution in
strategy—one in which the avoidance of armed conflict, or the containment of it, were
practically the only permissible objectives. 4 While Brodie’s assertion about a revolution
in strategy is debatable, his argument captures what would become the two central
concerns of the Cold War era: avoiding war and, if it could not be avoided, containing or
limiting it.
The first concern, avoiding armed conflict, became the preoccupation of a new brand of
deterrence theory, one in which nuclear arsenals played a key role. While some scholars
would define deterrence broadly to mean dissuading an adversary from taking any
undesirable action, this definition is too general for the purposes of this lesson. Here,
deterrence is defined more narrowly to mean dissuading a would-be aggressor from
launching a major attack against oneself or one’s allies.
To be sure, the concept of deterrence is as old as war itself. It has always been true that
one way to deter potential aggressors is to maintain a strong defense. However, it has
also always been true that the effectiveness of a strategy of deterrence depends upon
perceptions, rather than realities. An aggressor bases his decision to attack not on
whether the defender is weak, but on whether he perceives the defender to be weak. It is
in the defender’s interest, therefore, to communicate that he is strong enough to make any
4
Bernard Brodie, The Absolute Weapon (New York: Harcourt, Brace, 1946).
Lesson 8, 7
attack unattractive. Yet, at the same time, he must not appear so strong as to pose a threat
to his neighbors, and thus invite a preemptive attack or other hostile action.
Communication is, thus, the first requirement of deterrence. The second requirement is a
viable capability. One has to have the capacity to inflict some sort of measurable harm.
The third requirement is credibility: what the defender communicates about his capability
must be seen as credible by others. Again, the physical capability itself may be without
value unless it is married with the willingness to use it. Often, the message must cut
across psychological and cultural lines. A message might be read one way in some
cultures, but differently in others.
A quick glance at history shows that the concept of deterrence has not, and cannot,
guarantee peace. The first and most obvious reason for this is that the concept assumes
all parties will calculate their intended actions on a cost-benefit basis, and—equally
important—that all of the costs are completely clear to them, and that none of the benefits
are exaggerated. In a perfect would that is a reasonable assumption; anywhere else, it is
problematic. A second reason is that the side attempting to deter a potential attacker
might, because of mirror imaging, apply the wrong threat. Self-destruction, as in the case
of suicide bombers, for instance, is desired by some adversaries, and so the threat of their
destruction will not deter them. It is simply the wrong threat for that particular kind of
attacker. A better way to deter a suicide bomber might be to show that he or she would
not kill enough innocent bystanders to make his or her self-destruction worthwhile. A
third reason deterrence sometimes fails is because of the intervention of friction and
chance. While the majority of wars are started intentionally, some result from accidents
and misperceptions. Humanity has not yet found a preventative cure for accidents.
Nuclear weapons added another dimension to the basic theory of deterrence.
The
destructive capability of such weapons and the speed with which they could be delivered
meant that states had little room for error in crisis situations.
Assessments of an
adversary’s capabilities, intentions, and likely responses to certain military actions had to
be accurate. Crisis scenarios were painstakingly war-gamed in advance, with branches
and sequels analyzed, and probabilities computed. A new school of thought known as
game or decision theory emerged to assist in that process. Multiple safeguards were built
Lesson 8, 8
into launch sequences, and the codes themselves were among a state’s most closely
guarded secrets. Still, great uncertainty existed, not only among leading decision makers,
but also among the public. Movies such as Fail Safe (1964) and Dr. Strangelove (1964),
though fictional, reflected the growing popular concern that something in the vast defense
apparatus would go wrong, and the elaborate triad of ballistic missiles, long-range
bombers, and nuclear submarines that was supposed to provide security might visit
catastrophe instead.
In 1959, a study by RAND analyst, Albert Wohlstetter, entitled The Delicate Balance of
Terror, showed that the concept of deterrence itself was based on capabilities that were of
relative value, and prone to change as new capabilities were developed. Wohlstetter not
only underscored the importance of maintaining a devastating second-strike or retaliatory
capability to discourage a Soviet first-strike, he also warned of the need to monitor the
strategic balance constantly. As the superpowers continued to develop and enhance their
strategic weapons, some contemporary technologies would inevitably become obsolete,
either by design or as a matter of course. Achieving deterrence was only half the battle,
as Wohlstetter pointed out, maintaining it was the other half. In other words, while the
concept of deterrence seemed intrinsically sound, its practical foundation appeared
disturbingly fragile.
Limited War as an Alternative
Brodie’s second concern, that of containing or limiting war, opened the door for a new
way of thinking about the use of armed force for strategic aims, as well as the nature of
those aims. Indeed, theory of limited war, as it came to be called, was seen, in part, as an
outgrowth of the so-called “Golden Age” of American strategic thought in the 1950s and
1960s. Robert E. Osgood (1921-1986) was perhaps the leading American theorist of
limited war from the 1950s to the 1970s. His seminal Limited War: The Challenge to
American Strategy (1957) set down the basic principles of the theory. 5
5
Robert E. Osgood, Limited War: The Challenge to American Strategy (Chicago: University of
Chicago, 1957); and Limited War Revisited (Boulder: Westview, 1979).
Lesson 8, 9
The most important of these was an emphasis on achieving a broader range of policy
objectives, rather than just military victory. As Osgood explained: the “purpose of war is
to employ force skillfully in order to exert the desired effect on the adversary’s will along
a continuous spectrum from diplomacy, to crises short of war, to an overt clash of arms.” 6
Adhering to this principle, instead of concentrating solely on destroying an opponent’s
armed forces, would make the use of military power more effective, yet safer, and
assuage the fears of those who believed that local crises might escalate into a nuclear
holocaust.
Osgood openly admitted that his limited-war theory was stimulated by the
Clausewitzian principle that armed force must serve national policy, and by the perceived
imperative of military containment in the nuclear age. He firmly believed that, even in an
age laboring under the shadow of nuclear escalation, the use of military force as a rational
extension of policy still had a place, providing one measured success “only in political
terms and not purely in terms of crushing the enemy.” 7
Similarly, Thomas C. Schelling (1921- ), a leading theorist of the then nascent concept of
coercive diplomacy, argued that one could apply military force not just to achieve the
complete overthrow of an opponent, as in World War II, but in more controlled and
measured ways—to coerce, intimidate, or deter an adversary—and thereby to accomplish
any number of aims short of total victory. 8 Both theorists thus contributed to shifting the
general thinking about war away from “victory,” per se, toward policy objectives, that is,
away from a predominant focus on the Clausewitzian grammar of war and toward
broader concepts of war’s logic.
Defining Limited War
Unfortunately, the term limited war became less precise the more it was used. Initially,
scholars and others in the defense community used the term to refer to limited objectives.
The Second World War (1939-1945) was a classic case in which the objectives—
unconditional surrender or regime change—were unlimited. The Korean conflict (19506
Robert E. Osgood, “The Post-War Strategy of Limited War: Before, During, and After Vietnam,” in
National Security Management: Military Strategy, Anthony W. Gray, Jr. and Eston T. White, eds.,
(Washington, D.C.: National Defense University, 1983), 179-218.
7
Osgood, Limited War, 22.
8
Thomas C. Schelling, Arms and Influence (New Haven: Yale University Press, 1966), 16, 34.
Lesson 8, 10
1953) began as an unlimited war, with both belligerents seeking to overthrow the other,
but changed into a limited one, with each side seeking a favorable negotiated settlement.
However, this category becomes complicated when one considers the Vietnam conflict.
The United States was fighting a war of limited aims, trying merely to keep the South
Vietnamese government intact. The North Vietnamese, on the other hand, were waging a
war of unlimited aims, directed at eliminating the South Vietnamese government and
uniting Vietnam under Communist control. So, in a very real sense, whether a war is
limited or unlimited sometimes depends on one’s perspective.
However, other types of “limitations” soon entered the equation. Wars could, after all, be
limited geographically. The Arab-Israeli wars, for instance, were limited to a geographic
region, as was the Indo-Pakistani war (1968), the Falklands war (1982), and the Kosovo
conflict (1999). In each case, the physical scope of military action remained contained,
even though in the case of the Kosovo conflict most of NATO’s airpower was involved.
Wars can also be limited by the means used to prosecute them. While the United States
pursued limited aims in the Vietnam War, it did, for a time, wage a massive bombing
campaign against Hanoi. Some might well argue that the wholesale bombing of civilians
hardly qualifies as a limited means. On the other hand, the United States did not employ
any nuclear weapons, though it had plenty of them, which would seem to support the case
for limited means. Under this criterion, the Korean conflict, too, would qualify as a
limited war, since both sides had weapons of mass destruction available to them, but
refrained from using them, even though rather large numbers of conventional forces were
employed.
Yet another category of limitation exists in which the belligerents agree to attack only
military targets, and to avoid, or at least to minimize, damage to noncombatants. This
approach nullifies the traditional premise of strategic bombing, which involved visiting
intolerable destruction on civilian population centers. However, the advent of precision
munitions in the 1970s and 1980s would rescue strategic bombing, as the possibility
emerged for attacking targets of military value while limiting collateral damage.
Difficulties with this category arise when one considers the basic premises of terrorism,
particularly its 21st century variant, where civilians are deliberately targeted, and in large
Lesson 8, 11
numbers, in an effort to cow governments into making policy choices favorable to the
terrorists. Under this category, the United States and its allies and coalition partners are
waging a limited war with their campaign against global terror, though their foes clearly
are not.
The underlying question regarding limited war is simply this—can the belligerent who
chooses to fight a limited war prevail against one who opts for an unlimited war? In most
cases, the answer depends on which categories are involved.
In other cases, the
categories may not matter. Successful strategy may depend more on practical skills—
such as being able to read one’s opponent—than on abstract concepts.
Although apparently a viable alternative to massive retaliation, the theory of limited war
drew a fair amount of criticism over the years, much of it pertinent. Perhaps the most
significant criticism is that limited war may well be a victim of its own success. While
limited war at first appeared to offer a flexible alternative to the strategy of massive
retaliation, it also undermined the concept of deterrence. Put differently, once statesmen
realized that wars could be fought in a constrained and yet successful manner, they
tended to resort to them more frequently. An increase in the frequency of wars also
drives up the probability that escalation will occur.
Limited war seemed to have
bypassed the threat of nuclear escalation, which was a mainstay of the concept of nuclear
deterrence. With more countries today developing nuclear programs, it may only be a
matter of time before a limited conflict escalates to an unlimited war, either inadvertently
or deliberately, and opens the door for the use of nuclear weapons.
Yet, the paradox is that an alternative approach loses its value unless is used. As
Kissinger aptly remarked in 1962: “A country not willing to risk limited war because it
fears that resistance to aggression on any scale may lead to all-out war, will have no
choice in a showdown but to surrender.” 9 If surrender was not a viable option during the
Cold War, it seems even less so today, in the era of global terrorism.
9
Kissinger, Necessity for Choice, 61.
Lesson 8, 12
Retrospects and Prospects
In retrospect, although the United States enjoyed nuclear primacy at the start of the Cold
War, its superiority had slipped by the early 1960s, as the Soviet Union began to increase
its capability to carry out a retaliatory second strike. At about the same time, American
nuclear deterrence policies moved away from massive retaliation, which was based on
the principle of “assured destruction,” meaning that the United States would respond with
enough force to ensure the destruction of the Soviet Union. Instead, the two superpowers
settled on a nuclear deterrence policy called mutual assured destruction (MAD), in which
meant that each nation had enough of a second-strike capability to ensure the destruction
of the other, even if it tried to launch a preemptive first strike. Yet, it quickly became
clear that MAD itself was insufficient, unless both parties agreed that the other’s second
strike was, in fact, capable of assured destruction, and that this policy was agreeable to
both. Hence, MAD gave way to mutual agreed assured destruction (MAAD). The
underlying deterrent principle, however, remained that of mutual assured destruction, and
so MAAD is sometimes shortened to MAD.
Despite agreeing to the principle of MAD, both the United States and the Soviet Union
continued to try to attain nuclear dominance throughout most of the Cold War. Both
expanded their nuclear arsenals, improving the accuracy and the lethality of their
weapons, targeting their opponent’s command-and-control systems, investing in missiledefense shields, building better attack submarines, as well as more accurate multiwarhead (MIRV) land- and submarine-launched ballistic missiles, and (for the United
States) stealthy bombers and cruise missiles. Neither side came close to gaining a firststrike capability, but neither was willing to risk falling behind. A nuclear arms race was
essentially occurring against the backdrop of nuclear deterrence, again pointing out the
inherent instability of the practice as opposed to the concept.
The prospects for deterrence in the new millennium are not clear. On the one hand, the
concept seems as sound as ever. One the other hand, its implementation faces a new
challenge in global terrorism. In practice, deterrence has not yet found a consistently
effective way to dissuade fanatical jihadism from attacking noncombatants. Perhaps the
Lesson 8, 13
appropriate mechanism will have to come from within the broader Muslim community,
as it increases its efforts to marginalize the jihadists.
Lesson 8, 14
[Insert the following photos and captions near the first mention of each of the
authors]
Herman Kahn was known by many nicknames, one of which was the “Nuclear Santa Claus,” because of his weight and
his theories about the use of nuclear weapons.
Robert E. Osgood served on the U.S. National Security Council from 1969-70, and was a member of the
Secretary of State's Policy Planning Council from 1983 to 1985.
Thomas C. Schelling in 2005, receiving his Nobel Prize in Economics.