Is war declining – and why?
Azar Gat
Department of Political Science, University of Tel Aviv
Abstract
The article reviews and assesses the recent literature that claims a sharp decrease in fighting and violent mortality rate
since prehistory and during recent times. It also inquires into the causes of this decrease. The article supports the
view, firmly established over the past 15 years and unrecognized by only one of the books reviewed, that the first
massive decline in violent mortality occurred with the emergence of the state-Leviathan. Hobbes was right, and
Rousseau was wrong, about the great violence of the human state of nature. The rise of the state-Leviathan greatly
reduced in-group violent mortality by establishing internal peace. Less recognized, it also decreased out-group war
fatalities. Although state wars appear large in absolute terms, large states actually meant lower mobilization rates and
reduced exposure of the civilian population to war. A second major step in the decline in the frequency and fatality of
war has occurred over the last two centuries, including in recent decades. However, the exact periodization of, and
the reasons for, the decline are a matter of dispute among the authors reviewed. Further, the two World Wars constitute
a sharp divergence from the trend, which must be accounted for. The article surveys possible factors behind
the decrease, such as industrialization and rocketing economic growth, commercial interdependence, the liberaldemocratic
peace, social attitude change, nuclear deterrence, and UN peacekeeping forces. It argues that contrary
to the claim of some of the authors reviewed, war has not become more lethal and destructive over the past two centuries,
and thus this factor cannot be the cause of war’s decline. Rather, it is peace that has become more profitable. At
the same time, the specter of war continues to haunt the parts of the world less affected by many of the above developments,
and the threat of unconventional terror is real and troubling.
Keywords
declining violence, declining war, evolutionary psychology, human history, human violence
When quite a number of scholars simultaneously and
independently of one another arrive at very similar conclusions
on an issue of cardinal theoretical and practical
significance, their thesis deserves, and has received, great
attention. The thesis is that war and violence in general
have progressively decreased in recent times, during the
modern era, and even throughout history. Of course,
despite their unanimity, all these scholars could still be
wrong. Indeed, each of them tells a similar story of people’s
disbelief at their findings, most notably that we live
in the most peaceful period in human history. Some of
them even explain the general incredulity by the findings
of evolutionary psychology according to which we tend
to be overly optimistic about ourselves but overly pessimistic
about the world at large. Having myself written
about the marked decrease in deadly human violence
(Gat, 2006), I agree with the authors’ general thesis.
However, their unanimity falters over, and they are less
clear about, the historical trajectory of and the reasons for
the decline in violence and war, questions that are as
important as the general thesis itself.
Hobbes was right, and Rousseau wrong, about
the state of nature
Steven Pinker’s The Better Angels of Our Nature (2011)
towers above all the other books surveyed here in size,
scope, boldness, and scholarly excellence. It has
Corresponding author:
azargat@post.tau.ac.il
Journal of Peace Research
1–9
ª The Author(s) 2012
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DOI: 10.1177/0022343312461023
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deservedly attracted great public attention and has
become a best-seller. Massively documented, this 800page
volume is lavishly furnished with statistics, charts,
and diagrams, which are one of the book’s most effective
features. The book, spanning the whole human past as
far back as our aboriginal condition, points to two major
steps in the decline of violence. The first is the sharp
decline in violent mortality which resulted from the rise
of the state-Leviathan from around 5,000 years ago. This
conclusion is based on the most comprehensive studies
of the subject published over the past 15 years (Keeley,
1996; LeBlanc, 2003; Gat, 2006), which demonstrate
on the basis of anthropological and archaeological evidence
that Hobbes’s picture of the anarchic state of
nature as a very violent one was fundamentally true. Pinker
rightly summarizes that violent mortality with the
rise of states dropped from a staggering estimated 15%
of the population, 25% of the men, in pre-state societies,
to about 1–5%. The main reason for this drop is the
enforcement of internal peace by the Leviathan, but also,
less noted by Pinker, lower mobilization rates and a
smaller exposure of the civilian population to war than
with tribal groups, as will be explained shortly.
This conclusion regarding the dramatic drop in violent
mortality with the transition to the state is at odds
with the claim made by Jack Levy & William Thompson
in their book, The Arc of War (2011). As the book’s title
implies, Levy & Thompson posit a great increase in warfare
during history, before a decrease during the past two
centuries. Thus, the book claims that mortality in fighting
greatly increased, ‘accelerated’ in the authors’ language,
with the transition to the state. They reach this
conclusion by making several mistaken assumptions.
First, although professing ignorance about the distant
past because of the lack of evidence on the behavior of
hunter-gatherer societies before the adoption of agriculture
some 10,000 years ago, they cite and are heavily
influenced by the old Rousseauite anthropology of the
generation after the 1960s, which recent studies have
refuted.
Obviously, one does not have to accept the above
findings regarding the pervasiveness and great lethality
of prehistoric warfare. But Levy & Thompson simply
do not engage with them. They accept as true the Rousseauite
premise that sparse human population could not
possibly have had that much to fight about. However,
recently extant hunter-gatherer societies prove the opposite.
Australia is our best laboratory of hunter-gatherer
societies, because that vast continent was entirely populated
by them and ‘unpolluted’ by agriculturalists,
pastoralists or states until the arrival of the Europeans
in 1788. And the evidence shows that the Australian
tribes fought incessantly with one another. Even in the
Central Australian Desert, whose population density was
as low as one person per 35 square miles, among the lowest
there is, conflict and deadly fighting were the rule.
Much of that fighting centered on the water-holes vital
for survival in this area, with the violent death rate there
reckoned to have been several times higher than in any
state society. In most other places, hunting territories
were monopolized and fiercely defended by huntergatherers
because they were quickly depleted. Even
among the Inuit of Arctic Canada, who were so sparse
as to experience no resource competition, fighting to
kidnap women was pervasive, resulting in a violent death
rate 10 times higher than the USA’s peak rate of 1990,
itself the highest in the developed world. In more hospitable
and densely populated environments casualties
averaged, as already mentioned, 15% of the population
and 25% of the men, and the surviving men were covered
with scars (Gat, 2006: chs 2, 6).
We are not dealing here with a piece of exotic curiosity.
Ninety-five percent of the history of our species
Homo sapiens sapiens – people who are like us – was
spent as hunter-gatherers. The transition to agriculture
and the state is very recent, the tip of the iceberg, in
human history. Furthermore, the human state of nature
turns out to be no different than the state of nature in
general. Here too, science has made a complete turnabout.
During the 1960s people believed that animals
did not kill each other within the same species, which
made humans appear like a murderous exception and fed
speculations that warfare emerged only with civilization.
Since then, however, it has been found that animals kill
each other extensively within species, a point pressed on
every viewer of television nature documentaries. There is
nothing special about humans in this regard. Thus, lethal
human fighting did not ‘emerge’ at some point in history,
as Levy & Thompson posit.
Violent death sharply decreased with the rise of
the Leviathan
As mentioned earlier and as Pinker well realizes, violent
mortality actually dropped steeply with the emergence of
the state-Leviathan. Here is where Levy & Thompson
make a second mistake. For measuring the lethality of
warfare they use evidence of battle mortality, but this
is highly misleading for various reasons. First, pre-state
tribes’ main fighting modes were not the battle but the
raid and the ambush – capturing the enemy by surprise
and often annihilating entire sleeping camps: men,
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women, and children. Second, the size of battles merely
indicates the size of the states and their armies, which are
obviously larger than tribal groups in absolute terms. Yet
the main question is relative casualties, what percentage of
the population died violently. And here the fact is that
while states and their armies grew by a factor of tens,
hundreds, and thousands, giving a spectacular impression
of large-scale fighting, relative casualties actually
decreased under the state, and not only because of internal
peace. Indeed, casualties decreased precisely because
states grew large.
Take Egypt, for example, part of the ‘acceleration’ of
war with the emergence of states in Mesopotamia, Egypt,
Greece, and China, according to Levy & Thompson.
The size of the Egyptian army with which Pharaoh
Ramses II fought the Hittite empire at the Battle of
Kadesh (commonly dated 1274 BCE) was 20,000–
25,000 soldiers. This was a very large army by the standards
of the time. Yet the total population of Egypt was
about 2–3 million, so the army constituted 1% of the
population at most. This was very much the standard
in large states and empires throughout history because
of the great financial and logistical problems of maintaining
large armies for long periods at great distances from
home. Thus, in comparison to the high military participation
rates of small-scale tribal societies, participation
rates, and hence war casualties, in large states’ armies
were much lower. Moreover, in contrast to the great
vulnerability of women and children in small-scale tribal
warfare, the civilian population of Egypt was sheltered by
distance from the theaters of military operations and not
often exposed to the horrors of war. Such relative security,
interrupted only by large-scale invasions, is one of
the main reasons why societies experienced great demographic
growth after the emergence of the state. It is also
the reason why civil war, when the war rages within the
country, tends to be the most lethal form of war, as
Hobbes very well realized.
Warfare and feuds in the pre- and earlymodern
eras
Levy & Thompson further posit that between the 14th
and early 19th centuries, Europe was the scene of a second
‘acceleration’ in the historical trajectory of violence.
This is very much in line with the prevailing perceptions
regarding early modern European history, but these perceptions
are most probably wrong, and for the same reason
as before: Levy & Thompson count absolute battle
casualties, and obviously states became more centralized
during this period and armies grew in number, so battles
also grew in size. Yet it was the anarchy and feudal fragmentation
in Europe between the fall of the Roman
Empire and 1200 that were responsible for the pervasive
insecurity and endemic violence that characterized the
Dark Ages and resulted in, among other things, a sharp
demographic decline. Again, small-scale usually meant
more, not less, violent mortality. The focus on early modern
Europe is misleading also in another way: in the late
Middle Ages the Mongol conquests inflicted on the societies
of China, Central Asia, and Eastern Europe casualties
and destruction that were among the highest ever
suffered during historical times. Estimates of the sharp
decline experienced by the populations of China and
Russia, for example, vary widely. Still, even by the lowest
estimates they were at least as great, and in China almost
definitely much greater, than the Soviet Union’s horrific
rate in World War II of about 15%.
The receding of medieval anarchy in the face of the
growing European state-Leviathans was the first step
towards a steep decline in the continent’s violent mortality
rate beginning in early modernity and continuing to
the present day. The studies and data cited by Pinker
with respect to the domestic aspect of this trend are
strikingly paralleled by those of Robert Muchembled’s
History of Violence (2012). The work of a historian, the
book meticulously documents, on the basis of French
legal records, a 20-fold decrease in homicide rates
between the 13th and 20th centuries. Earlier studies of
other parts of Europe, starting with Gurr (1981), have
come up with similar findings. Like Pinker,
Muchembled attributes the steep decline to the state’s
growing authority, as its justice system effectively
replaced and deterred ‘private justice’, vendetta, and pervasive
violence, all of them endemic in unruly societies.
Correspondingly, again like Pinker, Muchembled
invokes Norbert Elias’s (2000) ‘civilizing process’,
whereby the defense of honor by sword and knife, a
social norm and imperative in most traditional societies,
is gradually given up among both the nobility and the
general populace.
The civilizing process is partly a function of the growing
authority of the state’s rule and justice system. But
there were other factors involved, which Pinker excels
in identifying and weaving together. Although he is not
a historian, his historical synthesis is exemplarily rich and
nuanced. He specifies the growing humanitarian sensibilities
in Europe of the Enlightenment, which he traces
to, among other things, the gradual improvement in living
conditions, growing commercial spirit and, above all,
the print revolution with the attendant values and habits
of reasoning, introspection, and empathy that it
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inculcated among the reading elites. As Pinker points
out, not only did homicide rates decline but also other
previously common forms of violence, such as judicial
disembowelment and torture, were becoming unacceptable
by the 18th century. This was the beginning of a continuous
process which during the following centuries
would bring about, among other things, the abolition
of slavery and the decline of capital punishment, tyranny,
and political violence in the developed world –
most notably in the areas where the values of Enlightenment
humanitarianism triumphed.
Both Pinker and Muchembled identify a change in
the trend towards increased violence and homicide rates
in the United States and Europe from the 1960s on.
They attribute this change (Pinker is particularly elaborative
here) to the erosion of public authority and some
reversal of the ‘civilizing process’ with the cults of youth
culture, defiance of authority, radical ideologies of
violence by the ‘oppressed’, and the fragmentation of the
stable family structure. Pinker identifies a return to a
downward trend in violence from about 1990 on, which
he attributes to an ebbing of much of the above through
reasserted state action and changes in the public mood. A
last point worth mentioning in this context:
Muchembled reveals that throughout the steep decline
in homicide rates, from medieval times to the present,
90% or more of all cases have been perpetrated by men,
especially between the ages of 20 and 30 years old. As
Daly & Wilson (1988: 145–149) have shown, this ratio
is found in each and every society studied around the
globe, from hunter-gatherers to agricultural and industrial
societies, irrespective of the vastly different homicide
rates among them.
The decline of war and the three ‘Long Peaces’
after 1815
We now move to the decline of war, which is our main
concern here. Most people are surprised to learn that the
occurrence of war and overall mortality in war sharply
decreased after 1815, most notably in the developed
world. The ‘Long Peace’ among the great powers after
1945 is more recognized and is widely attributed to the
nuclear factor, a decisive factor to be sure, which concentrated
the minds of all the protagonists wonderfully. The
(inter-)democratic peace has been equally recognized.
But in actuality, the decrease in war had been very
marked before the nuclear era and encompassed both
democracies and non-democracies. In the century after
1815, wars among economically advanced countries
declined in their frequency to about one-third of what
they had been in the previous centuries, an unprecedented
change. Indeed, the Long Peace after 1945 was
preceded by the second longest peace among the great
powers, between 1871 and 1914, and by the third longest
peace, between 1815 and 1854 (Gat, 2006: 536–
537, 608). Thus, the three longest periods of peace by
far in the modern great powers system all occurred after
1815. Clearly, one needs to explain the entire trend,
while also accounting for the glaring divergence from
it: the two World Wars.
Is modern war more lethal and destructive than
before?
In his earlier works, Levy (1983) was among the first to
document the much-reduced frequency of war after
1815. But what brought about this change? Levy &
Thompson assume – this is perhaps the most natural
hypothesis – that wars declined in frequency because
they became too lethal, destructive, and expensive. Supposedly,
a trade-off of sorts was created between the
intensity and frequency of warfare: fewer, larger wars
supplanting many smaller ones. This hypothesis barely
holds, however, because, again, relative to population and
wealth wars have not become more lethal and costly than
earlier in history. Furthermore, as Levy & Thompson
rightly document, the wars of the 19th century – the
most peaceful century in European history – were particularly
light, in comparative terms, so there is no trade-off
here. True, the World Wars, especially World War II,
were certainly on the upper scale of the range in terms
of casualties. Yet, as already noted, they were far from
being exceptional in history. Once more, we need to
look at relative casualties, general human mortality in
any number of wars that happen to rage around the
world, rather than at the aggregate created by the fact
that many states participated in the World Wars.
I have already mentioned the Mongol invasions, but
other examples abound. In the first three years of the
Second Punic War, 218–16 BCE, Rome lost some
50,000 citizens of the ages of 17–46, out of a total of
about 200,000 in that age demographic (Brunt, 1971).
This was roughly 25% of the military-age cohorts in only
three years, the same range as the Russian and higher
than the German rates in World War II. This, and the
devastation of Rome’s free peasantry during the Second
Punic War, did not reduce Rome’s propensity for war
thereafter. During the Thirty Years War (1618–48) population
loss in Germany is estimated at between one-fifth
and one-third – either way higher than the German casualties
in World War I and World War II combined.
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People often assume that more developed military
technology during modernity means greater lethality and
destruction, but in fact it also means greater protective
power, as with mechanized armor, mechanized speed
and agility, and defensive electronic measures. Offensive
and defensive advances generally rise in tandem. In addition,
it is all too often forgotten that the vast majority of
the many millions of non-combatants killed by Germany
during World War II – Jews, Soviet prisoners of war,
Soviet civilians – fell victim to intentional starvation,
exposure to the elements, and mass executions rather
than to any sophisticated military technology. Instances
of genocide in general during the 20th century, much as
earlier in history, were carried out with the simplest of
technologies, as the Rwanda genocide horrifically
reminded us.
Nor have wars during the past two centuries been economically
more costly than they were earlier in history,
again relative to overall wealth. War has always involved
massive economic exertion and has been the single most
expensive item of state spending (e.g. massively documented,
Bonney, 1999). Examples are countless, and it
will suffice to mention that both 16th- and 17thcentury
Spain and 18th-century France were economically
ruined by war and staggering war debts, which in
the French case brought about the Revolution. Furthermore,
death by starvation in premodern wars was
widespread.
Is it peace that has become more profitable?
So if wars have not become more costly and destructive
during the past two centuries then why have they
receded, particularly in the developed world? The
answer is the advent of the industrial–commercial revolution
after 1815, the most profound transformation
of human society since the Neolithic adoption of agriculture.
The correlation between the decline of war in
the developed world and the process of modernization,
both unfolding since 1815, is surely not accidental, and
the causation is not difficult to locate. In the first place,
given explosive growth in per capita wealth, about 30to
50-fold thus far, the Malthusian trap has been broken.
Wealth no longer constitutes a fundamentally
finite quantity, and wealth acquisition progressively
shifted away from a zero-sum game. Secondly, economies
are no longer overwhelmingly autarkic, instead
having become increasingly interconnected by specialization,
scale, and exchange. Consequently, foreign
devastation potentially depressed the entire system and
was thus detrimental to a state’s own wellbeing. This
reality, already noted by Mill (1848/1961: 582), starkly
manifested itself after World War I, as Keynes (1920)
had anticipated in his criticism of the reparations
imposed on Germany. Thirdly, greater economic openness
has decreased the likelihood of war by disassociating
economic access from the confines of political
borders and sovereignty. It is no longer necessary to
politically possess a territory in order benefit from it.
Of the above three factors, the second one – commercial
interdependence – has attracted most of the attention
in the literature. But the other two factors have
been no less significant.
Thus, the greater the yield of competitive economic
cooperation, the more counterproductive and less attractive
conflict becomes. Rather than war becoming more
costly, as is widely believed, it is in fact peace that has
been growing more profitable. Referring to my argument
in this regard, Levy & Thompson (2011: 72–75)
excused themselves from deciding on the issue on the
grounds of insufficient information regarding the cost
of premodern war. But as already noted, the information
on the subject is quite clear.
In this limited framework I can only briefly mention
the main reasons for the continued outbreak of war during
the past two centuries. In the first place, ethnic and
nationalist tensions often overrode the logic of the new
economic realities, accounting for most wars in Europe
until 1945. They continue to do so today, especially in
the less developed parts of the globe, the world’s remaining
‘zone of war’. Additionally, the logic of the new economic
realities receded during the late 19th and early
20th centuries, as the great powers resumed protectionist
policies and expanded them to the undeveloped parts of
the world with the New Imperialism. This development
signaled that the emergent global economy might
become partitioned rather than open, with each imperial
domain becoming closed to everybody else, as, indeed,
they eventually did in the 1930s. A snowball effect
ensued, generating a runaway grab for imperial territories,
Lebensraum, and ‘co-prosperity spheres’. Here lay
the seeds of the two World Wars. Furthermore, the
retreat from economic liberalism in the first decades of
the 20th century spurred, and was in turn spurred by,
the rise to power of anti-liberal and anti-democratic
political ideologies and regimes incorporating a creed
of violence: communism and fascism.
Indeed, although non-liberal and non-democratic
states also became much less belligerent during the industrial
age, it is the liberal democracies that have been the
most attuned to its pacifying aspects. This applies most
strikingly to the democracies’ relations among themselves,
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but, as scholars have become increasingly aware, also to
their conduct in general. Pinker examines in great detail
and nuance the various aspects in the unfolding process
over the past centuries, which he labels the humanitarian
revolution, the rights revolution, and the democratic, liberal
and capitalist peace. Some of the other books surveyed
here are more problematic in this respect.
A successful UN?
Joshua Goldstein, Winning the War on War (2011), is in
many ways two books under one cover – the first is very
ambitious, the other more limited. Both are very good,
yet they do not always sit quite comfortably together.
The beginning of the book (specifically chapter 2) is similar
to Pinker’s in boldly and effectively advancing the
wide-ranging thesis that war has decreased in stages
throughout human history and in recent times. Goldstein,
relying on pretty much the same studies and data
as Pinker, albeit in lesser detail, arrives in his opening
expose´ at more or less the same conclusions regarding the
long-term historical trend. As he suggests, the more we
travel back into the past the more warlike it becomes
(as predominantly measured by mortality rates): the past
ten years compared with the previous ten; the post-Cold
War era compared with the Cold War; the Cold War era
compared with that of the World Wars; the past century
compared with previous centuries (the peaceful 19th
century is silently smoothed over here); the modern era
(past 500 years) compared with premodern history; historical
times compared with prehistory.
The remaining 90% of the book is a different breed
altogether. It is a history of UN and other peacekeeping
operations from 1947 to the present, analyzing their
effect in decreasing warfare in various regions of the
developing world. In this portion of the book Goldstein
has many achievements as well. The historical study and
analysis are learned and sensible. More importantly,
Goldstein succeeds in making a case for a claim that is
generally met with much skepticism: that peacekeeping
forces have actually had a not insignificant effect in quelling
open violence, shortening wars and thereby reducing
war mortality and, in some instances, even in contributing
to a peaceful conflict resolution. It falls beyond the
scope of this article to offer a critical review of the exact
political conditions and specific circumstances in terms
of the local and international players and interests under
which lesser or greater success has been achieved in some
cases. Side by side with the discerning political scientist,
there appears to be in Goldstein a true believer and crusader
in the cause of peace for whom peacekeeping
missions and the activity of peace movements are a panacea
and the main reason behind the writing of the book.
Indeed, it is the connection between the two parts of the
book, between the long-term and more recent decrease
in war, on the one hand, and the role of peacekeeping
in reducing warfare, on the other, that constitutes the
book’s weakest link.
The question of causality is where Goldstein stands on
shaky ground. Had he been content with the modest
argument that peacekeeping operations have contributed
something to the decrease of warfare over the past 65,
especially the last 20 years, and made an effort to weave
this factor together with other factors so as to clarify their
mutual connections and interactions and make sense of
the overall picture, this would have been a very reasonable
approach. Indeed, Goldstein cites (p. 15) with seeming
approval the list of factors generally regarded as
contributing to the decrease of war: from US hegemony,
to the effect of liberalism, democracy, and global capitalism,
to female participation in politics (all of them, incidentally,
not mutually unrelated). Yet later (pp. 42–45)
he summarily plays down any other explanation for the
recent decrease of war as if it were competing with rather
than complementary to peacekeeping. This is curious,
unnecessary and, indeed, self-contradictory. After all,
temporally, it is Goldstein himself who claims that the
decrease in warfare had begun long before the UN and
its peacekeeping operations. Moreover, spatially, the
world’s remarkable zone of peace – the scene of the most
dramatic change – is not the developing world but the
affluent, developed world, especially its liberal democratic
parts, where no peacekeeping forces and operations,
by the UN or anybody else, have played a role.
In response to the claim that he had little by way of theory,
Goldstein replied in a 2012 International Studies
Association panel1
that his was international liberalism.
But is international liberalism unrelated to the growth
of liberalism in general – both political and economic –
with its broader, well-documented pacifying effects
projected from the hegemonic liberal core to the less
liberal periphery?
Simply kicking a senseless habit?
An untempered idealistic, almost salvationist, streak is
the cause of considerable problems and confusion in
John Horgan, The End of War (2012). The author is very
1
In a panel on ‘The decline of violence: Current trends’, 53rd
Annual Convention of the International Studies Association, San
Diego, CA, 2 April.
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familiar with the literature relating to the subject and has
many correct things to say: like the others, he documents
the great decline in warfare around the world; and rejecting
the crude biological determinism often cited as the
cause of war and of war’s inevitability, he points out that
both war and peace are in our genes. And yet he fails to
grasp the full significance of this point. In pursuit of their
aims people may employ any of the following strategies:
cooperation, peaceful competition, and violent conflict.
We are very adept in using each of them because we are
evolutionarily well-equipped with the heavy biological
machinery necessary for carrying them out. The reason
why we are so well equipped is that each of these strategies
has been widely employed by humans throughout
our long evolutionary history. Each of them is a welldesigned
tool interchangeably resorted to, depending
on the particular circumstances and prospects of success.
Violence is not a blind biological instinct, but nor does it
lack a deep-rooted, evolution-shaped biological function.
It is the hammer in our behavioral toolkit, which has
always been readily disposable and handy; indeed, it
often proved necessary and advantageous. The abovecited
huge disparity between men and women among
killers, which remains constant despite huge differences
in killing rates among different societies, is a striking
demonstration of both the innate element and great
context-sensitivity of violent behavior.
A failure to grasp this crucial point (which Pinker
well emphasizes) is the cause of many fatuous ideas in
Horgan’s book. He has been convinced by the recent
literature on the subject that extensive warfare had
existed before the state and agriculture. Yet despite the
evidence to the contrary (e.g. Australia, Tasmania, the
Arctic), he clings to the view that warfare had begun
only with the denser human populations forming
shortly before the agricultural revolution. He repeats
Margaret Mead’s idea (1940) that war was an addictive
invention, somehow – it is not clear why – picked up by
human populations throughout the world (one wonders
if the same applies also to homicide). Apparently,
Horgan believes that the alleged ‘invention’ of war at
some point in history strengthens the case that it is not
pre-ordained and gives credence to the proposition that
this arbitrary and senseless habit is, and should be, now
kicked, ‘uninvented’, as suddenly and inexplicably as it
was invented, by an act of sheer moral will. He states
that he has always believed war to be crazy and absurd,
devoid of any rationale. This is a growing sentiment in
today’s modern and affluent world. But try this thesis
on Chinggis Khan, whose descendants constitute,
according to genetic studies (Zerjal et al., 2003), 8%
of all males in Eastern and Central Asia, evidence of
staggering sexual opportunities enjoyed by his sons and
grandsons whose houses ruled over the area for centuries.
Lest it be thought that only autocrats and other
‘rotten apples’ profited from war, it ought to be remembered
that the two most successful war-making citystates
of classical antiquity were democratic Athens and
republican Rome. And they were so successful precisely
because the populace in these polities benefited from
war and imperial expansion, championed them, and
enlisted in their cause.
To account for the perceived decrease in warfare,
Horgan resorts to a purely voluntary explanation. He
adheres to John Mueller’s thesis (1989) that the decline
of war is the product of a social ‘attitude change’. Why
this attitude change occurred at this point in history
rather than any time earlier remains a mystery with both
Mueller and Horgan. Horgan posits people’s free will as
moral agents, yet powerful moral doctrines such as
Buddhism and Christianity decried war for millennia
without this having any noticeable effect. To understand
the gravitation of human choices, and norms, from
violent conflict towards the nonviolent options of
cooperation and peaceful competition, one needs to
understand the changing circumstances and calculus of
cost-effectiveness during the past two centuries and in
recent decades, as mentioned above.
Pinker well understands this logic, but some of the few
major reservations I have about his book concern the
causes of violence. Surprisingly, the evolutionary parts of
the book are, in my opinion, inferior to the historical
parts. ‘Angels’ versus ‘Demons’ in the human behavioral
system is an allusion to Lincoln’s first inaugural address
and is surely invoked metaphorically. And yet, not
entirely, because to reduce central aspects of human behavior,
including those Pinker labels predation, dominance,
and ideology, to ‘demons’ is to flatten the major subject of
human aims and motivations as well as the means for
achieving them. Pinker cites studies showing that separate
parts of the brain may trigger violent behavior, and this is
of course true of nearly all behaviors. But this does not
mean that all violent behaviors are not subject to, regulated,
and shaped by a unified evolutionary calculus of survival
and reproduction, the very definition of the
evolutionary rationale, which Pinker as an evolutionist
would surely be the first to accept. The wide category
he calls predation violence and describes as a means to
achieve an end in fact also covers most of the other
motives for violence he cites. Thus, the quest for dominance
among all social animals is an evolutionary means
to achieve preferential access to resources and superior
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sexual opportunities. Furthermore, dominance can be
pursued peacefully as well as violently (as it generally is
in modern and liberal societies), which makes the ‘demon’
category all the more awkward. The same, of course,
applies to ideology, which is another of Pinker’s ‘demons’.
Revenge, yet another ‘demon’, is also, as Pinker recognizes,
a means to an end: it is intended to foster deterrence
by demonstrating that one is not a pushover. It is the main
means for establishing fragile security in all unruly societies.
Finally, Pinker on occasion gives the impression that
the decline of war is a matter of escaping a Prisoner’s
Dilemma. While there are all sorts of Prisoner’s Dilemmas
in conflict situations, not all conflicts fall under this category.
Throughout human history there have been many
winners and losers in war.
Future prospects and threats
One more point: Pinker wisely argues that he is not prophesying
the future but simply describing past trends
and their historical explanations. He agrees that such
trends, however deep-rooted – and they are – may
reverse, as with the potential changes in the global balance
of power with the weakening of US and Western
hegemony, the rise of a non-democratic, non-liberal
China (if it so remains) and the like. In discussing the
prospect of unconventional terror, Pinker claims, like
some others, that the threat is much overrated, emphasizing
the difficulties surrounding the acquisition and
successful use of nuclear weapons by terrorists. However,
he ignores the more relevant threat, that of biological
weapons, magnified and widely disseminated thanks to
today’s biotechnological revolution. Biological weapons
are potentially as lethal as nuclear weapons, and far easier
to acquire and use even by non-state individuals or small
groups. Not only might a successful attack result in casualties
on a par with the USA’s greatest wars; it is likely to
target its main centers of population and the economy. I
would not underestimate this threat. More generally, we
are clearly experiencing the most peaceful times in history
by far, a strikingly blissful and deeply grounded
trend. Yet the observation that at least since 1945 this
is also the most dangerous world ever, with mankind for
the first time possessing the ability to destroy itself
completely, civilian populations held hostage to MAD
(mutually assured destruction) deterrence, and even individuals
and small groups gaining the ability to cause mass
death, is far from a cliche´.
Towards the end of this survey one should also mention
Jesse Richards, The Secret Peace (2010). The subtitle
of this excellent book, Exposing the Positive Trend of World
Events, is more reflective of its content, because the book is
not concerned with the decline of war alone but documents
the massive improvement in major aspects of
human life during modernity. Sweeping and effectively
written, and as well illustrated as Pinker’s book with data,
charts, and diagrams, it negates widespread sentiments,
reinforced by the current economic crisis. There are many
challenges on the horizon, in the security as well as in
other fields. But given the past record and accelerating
success during modernity, we should hope that, despite
ups and downs, the general trends will endure.
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AZAR GAT, b. 1959, DPhil in History (University of
Oxford, 1986); Ezer Weitzman Professor of National
Security, Political Science Department, Tel Aviv University;
recent books: War in Human Civilization (Oxford
University Press, 2006); Victorious and Vulnerable: Why
Democracy Won in the 20th Century and How It Is Still
Imperiled (Hoover Institution, Rowman & Littlefield,
2010); Nations: The Long History and Deep Roots of Political
Ethnicity and Nationalism (Cambridge University Press,
2013).
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