Since the end of World War II the global security environment has undergone a series of profound changes whose causes remain curiously little examined—even by security analysts.
As Figure 1 (below) reveals, the total number of conflicts—international and civil wars—being waged around the world increased threefold during the Cold War years, then sharply declined, with this latter change going largely unheralded, even at the United Nations.
The forces that have been driving this decline are likely to be sustained, or to increase, in the years ahead, providing grounds for cautious, qualified optimism about future security trends.
Patterns of Warfare in the Post-Cold War World
Almost all of the increase in conflict numbers from the end of World War II until the end of the Cold War is accounted for by the proliferation of intrastate conflicts—civil wars. But, as Figure I indicates, following the end of the Cold War, the number of conflicts—almost all intrastate—dropped sharply. By 2008, there were a third fewer conflicts than in 1992.
From 2003 to 2008, overall conflict numbers increased by some 25 percent. This was due primarily due to an increase in minor conflicts that kill relatively few people. But the number of high-intensity wars, those with an annual battle death toll of 1,000 or more, has continued to decline. By 2008 there were 78 percent fewer of these conflicts being fought around the world than at the end of the 1980s.
Remarkably, not a single full-length study has been devoted to explaining why this extraordinary reduction in conflict numbers—almost all of which were civil wars—has taken place.
How Wars Have Become Less Deadly
The average war in the 1950s killed about 10,000 people a year; in the new millennium the average was a little less than one thousand.
The remarkable but extremely uneven reduction in death tolls revealed in Figure 2 has been caused in part by the long-term decline in international conflicts (which kill far more people on average than civil wars), and by the sharp decline in the direct and indirect military interventions by the superpowers in other countries’ wars that were characteristic of the major conflicts of the Cold War years. These conflicts—from the Chinese Civil War and the Korean and Vietnam Wars, to the Soviet invasion and occupation of Afghanistan—typically involved prolonged engagements between huge armies, at least one of which was equipped with heavy conventional weapons—strike aircraft, tanks, long-range artillery and the like. Death tolls often exceeded 1 million.
In the post–Cold War world, wars are mostly fought within, not between, states and by small armies mostly equipped with small arms and light weapons. While often characterized by extreme brutality toward civilians, these wars have killed relatively few people compared to the major wars of the Cold War period.
And it is not just battle deaths that have declined. Deaths from conflict-exacerbated disease and malnutrition have also been reduced by long-term improvements in public health, notably immunization, that have caused child and adult mortality rates to decline sharply across the developing world over the past 30 years. These improvements have not only steadily reduced mortality rates in peacetime but also saved countless lives in wartime.
In addition there have been major increases in the level, scope, and effectiveness of humanitarian assistance to war-affected populations in countries in conflict. These interventions have reduced wartime death tolls still further.
Can We Be Confident About the Trends?
These findings present a picture that is very much at odds with popular—mostly media-derived—depictions of a progressively more violent world. And they raise an obvious question: how reliable are the data? The short answer is that we can be quite confident about the number of conflicts, but battle death data are far less reliable. Exaggerated, politically driven claims about death tolls are common in some conflicts, while undercounting is a problem in most—particularly in wars in very poor countries. But there is no doubt that the 50-plus year trend in battle-related deaths is downward—no serious scholar would deny that today’s wars are, on average, far less deadly than those of the Cold War years.
Predicting future security trends is an exercise fraught with peril, as the near-universal failure of the security studies community to predict the end of the Cold War reminds us. But while current statistical models do very poorly at predicting exactly when and where wars will start, considerable progress has been made in establishing the conditions, dynamics, and policies that increase—and decrease—the risks that countries will succumb to war.
It is ironic given the huge and sometimes disproportionate attention paid to the risks of war and terrorism, to say nothing of some 1.5-plus trillion dollars a year being devoted to military expenditure around the world, that there has been far less attention paid to what prevents or stops wars than what causes them. As Australian historian Geoffrey Blainey succinctly put it, “For every thousand pages on the causes of war, there is less than one page directly on the causes of peace.”
Understanding the drivers of peace in the post–World War II world at minimum requires explaining the decline international conflicts since the 1950s, and decline in civil wars since the end of the Cold War. The next two sections attempt this, while the final section reflects on the implications these analyses for global security over the next decade.
Explaining the 60-Year Decline in the Incidence of International Conflict
In the 1950s, there were, on average, just over six international conflicts being fought around the world each year, anti-colonial conflicts included. In the new millennium there has been fewer than one international conflict each year on average, as Figure 3 makes clear.
Moreover, there has not been a single war between the major powers for an unprecedented 60-plus years. This does not mean that the major powers are war-averse—far from it. In fact France, the United Kingdom, the United States, and Russia (USSR) top the list of countries that have fought the most wars since 1946—though their wars were almost all fought in poor countries and never against other major powers.
International conflicts are not only fewer in number, they have also become far less deadly. In the 1950s, the average international conflict killed some 20,000 people a year on the battlefield. In the post–Cold War 1990s, the average annual battle-death toll was less than 6,000; in the new millennium the figure was around 3,000.
International relations scholars have offered a number of—contested—explanations for the causes of war and peace in the nuclear age. However, notwithstanding heated debates among their proponents, most of the contested theories are complementary.
A Nuclear Peace?
For “realist” scholars, the absence of war between the major powers during the Cold War years is best explained by the existence of a stable balance of power between East and West—in particular by the deterrence created by the mutual possession of nuclear arsenals with “second strike” capacities.
Kenneth Waltz, the leading proponent of the pacifying impact of nuclear weapons, has argued that, “Peace has become the privilege of states having nuclear weapons, while wars are fought by those who lack them.”
But while nuclear arsenals undoubtedly induced a measure of caution in the behaviour of the superpowers and their allies towards each other, Waltz’ assertion is wrong for two reasons.
First, nuclear weapons states are not embroiled in fewer wars. Quite the contrary. Each of the four countries that have fought most international wars since the end of World War II—France, the United Kingdom, the United States, and Russia (USSR)—is a nuclear weapons state.
Second, since the end of World War II, non-nuclear states have repeatedly attacked nuclear weapons states. U.S. nuclear weapons did not deter China from attacking U.S. forces in the Korean War, nor North Vietnam from attacking South Vietnam and U.S. forces in the 1960s. Israeli nuclear weapons did not dissuade Egypt from attacking Israel in 1973. British nuclear weapons did not deter Argentina from invading the Falkland Islands in 1982, and the Soviet nuclear arsenal did not deter the mujahedeen from waging war against the Soviet army in Afghanistan in the 1980s—nor did they prevent a Soviet defeat.
Peace Through Democratization and Interdependence
“Liberal” scholars, who have a much less pessimistic view of human nature and institutions than “realists,” believe that the incidence of war between states has been reduced since the end of World War II by the steady growth in the number of democracies in the international system and by growing international economic interdependence.
The best-known liberal theory is the “democratic peace,” whose central—and uncontested—finding is that fully democratic states never, or to be more precise, almost never, go to war against each other.
Proponents of democratic peace theory do not argue that democracies are generally peaceful—democracies frequently fight non-democracies—simply that democratic states do not fight each other. If the democratic peace theory is correct, the dramatic increase in the number of democracies around the world over the last three decades will have reduced the number of countries in the world likely to fight each other.
Other liberal scholars place much less stress on the conflict-reducing effect of democracy and a lot more on the security impact of the ever-growing interdependencies that are associated with today’s globalized economy. Interdependence increases the costs of going to war, while reducing its benefits. One study by the Cato Institute argued that when measures of both democratization and economic liberalization are included in statistical analyses, “economic freedom is about 50 times more effective than democracy in diminishing violent conflict.”
The debate among quantitative scholars over the relative impacts of democracy and economic interdependence on the risk of war is both unresolved and highly technical, but there is little dissent from the proposition that increasing levels of international trade and foreign direct investment (FDI) are associated with a reduced risk of war.
But increased interdependence is not the only economic driver of reduced war risks. In the modern era there are far fewer economic incentives for embarking on war than there were in the era of colonial expansion. Today it is almost always cheaper—politically as well as economically—to buy raw materials from other countries than to mount invasions in order to seize them.
Peace through Ideas: The Change in Attitudes to War
In the 21st century the traditional economic benefits of conquest have not only largely disappeared, but the resort to war as an instrument of statecraft has become legally and normatively proscribed except in self-defence, or with the authorization of the UN Security Council.
This shift in global norms is evident in the universal recognition of the illegitimacy of colonial conquest and the absence among national governments the world over of the sort of aggressive hyper-nationalism associated with German and Japanese Fascism prior to World War II. What the French call bellicisme—the glorification of warfare—has almost completely disappeared from the developed world and is very rare elsewhere—though it is characteristic of some radical Islamist organizations like al Qaeda.
The importance of the anti-war norm is not negated by the fact that it is sometimes violated. All norms are violated to some degree. This does not mean that they are ineffectual.
Explaining the Decline in Civil Wars
The most robust finding to have emerged from two decades of statistical research on the causes of war is that there is a strong association between rising levels of economic development and the risk of war onsets. As national incomes increase, the risk of war declines. Economic development, in other words, appears to be a powerful long-term form of conflict prevention.
Several reasons have been advanced to explain why higher incomes should be associated with reduced risks of civil war. The most compelling and best supported, is that income is a “proxy” indicator for state capacity. As national incomes rise, tax revenues increase and state capacity grows. This in turn provides governments with the political, economic, and military resources to prevent rebellions—and to crush militarily those that cannot be stopped via negotiation, or by buying off grievances, or political co-optation.
Rebel groups, often living in the rural periphery, are generally excluded from the benefits of rising levels of development, so the balance of resources relevant to preventing wars, and winning those that cannot be prevented, will—other things being equal—tilt progressively in favour of governments as incomes rise.
Given that economic growth generally increases the capacities of governments relative to those of insurgent organizations, we might expect to see fewer insurgent victories as poor-country incomes rise.
This is in fact the case. In East and Southeast Asia, for example, there hasn’t been a single insurgent military victory since the end of the 1970s, while among the “strong” states of the Middle East and North Africa, there has been just one (Yemen) in the same period. The greatest number of insurgent victories over the past 30 years has been in sub-Saharan Africa—the region with the weakest states.
If, as seems likely, poor-country incomes continue to rise, the prospect for insurgent victories will continue to decline. Confronting diminishing returns from political violence, some would-be rebels may in future be deterred from starting wars.
The Impact of the End of the Cold War
The extraordinary post-Cold War decline in the number of high-intensity conflicts went largely unnoticed in the policy community, the media, and by many in the research community. In the 1990s this was perhaps not surprising. Most people believed that conflict numbers were increasing—and they were partly correct. In fact, twice as many conflicts started in the 1990s, as in the 1980s. But an even greater number of conflicts ended in the latter decade. It was this little-recognized development that led to the net decline in conflict numbers.
The end of the Cold War directly caused, or indirectly catalyzed, a series of changes that had a major impact on the global security landscape.
First, the deep ideological division that had driven conflicts both between and within states in the international system for more than 40 years simply disappeared.
Second, the flow of resources from the United States and the Soviet Union and their allies to the warring parties in various “proxy” wars in the developing world simply shrivelled up. One consequence was the ending of “…nearly all the large scale communist insurgencies in the world.”
Third, the UN, freed from the political stasis imposed by more than four decades of East-West rivalry, spearheaded an extraordinary upsurge of security initiatives by the international community.
Most notable were “peacemaking” (UN-speak for negotiations to end wars) and post-conflict “peacebuilding,” whose central security task, as its name suggests, is to prevent wars that have ended from starting again.
Preventive diplomacy was talked about a great deal but little practised. This was in part because the UN Security Council is so consumed by the demands of constant crisis management that it has little time to pursue prevention initiatives, and in part because many states in the developing world worried that inviting the UN in to play a dispute resolution role would give unwanted international legitimacy to insurgent groups.
The UN was not alone in its security activism, of course. The World Bank, other international agencies, regional security organizations, donor governments, and huge numbers of international NGOs (nongovernmental organizations) were also actively involved, as were the national governments and national NGOs of the war-affected countries.
The increase in the level of international security activism has been extraordinary. It has included:
- A threefold increase in UN and non-UN peace operations from 1988 to 2008—there are currently more than 30 such operations underway around the world, with a comparable number of non-UN missions in the field.
- An increase in UN Security Council “Chapter VII” resolutions from zero in 1989 to 40 in 2008. Chapter VII resolutions authorize the Security Council to respond to threats to the peace with military force, sanctions, or other means.
- A fivefold increase between 1989 and 2008 in the number of Special Representatives of the Secretary-General of the UN, most of whom have a security-related mandate.
- A tenfold increase between 1991 and 2001 in the number of “Friends of the Secretary-General,” “contact groups,” and other political arrangements that support peacemaking and post-conflict peacebuilding initiatives.
- A thirteenfold increase in the number of multilateral sanctions regimes in place each year between 1991 and 2008.
- A ninefold increase in the number of ongoing disarmament, demobilization, and reintegration operations from 1989 to 2008.
In some important areas—notably mediation initiatives to end civil wars—we still lack reliable global data. But, there is little doubt that the trends are similar.
Some Causes for Optimism
The security history of the post–World War II era, despite some major failures, provides grounds for some cautious optimism about the future—though none for complacency.
Two system-wide drivers of armed conflict—the imposition of colonial rule on much of the developing world and the Cold War—ceased to exist in this period. Neither will return. No obvious new system-wide source of conflict appears likely to replace them.
Some might argue that the threat of Islamist radicalism exemplified by al Qaeda is already a major threat to international security. But support for extremist Islamist ideology has declined substantially throughout the Muslim world. Absent popular support, Islamist radicals cannot wage a successful “peoples’ war,” and without conventional armies, which they do not have, they cannot overthrow governments. It appears extremely unlikely that radical Islamists can ever energize an effective global campaign comparable to the anti-colonial and Marxist political movements of the Cold War period.
There are other reasons for cautious optimism. First, absent a global economic crisis that is far greater than the current one, economic interdependence will continue to grow. This will likely further increase the costs and decrease the benefits of interstate war—and hence the risk of it occurring.
Second, incomes will almost certainly continue to grow in the developing world. This will continue to enhance state capacity, which almost all the statistical studies agree reduces the risks of armed conflict.
Third, there are no signs that the international community’s commitment to peacemaking and peacebuilding is waning—indeed the contrary is true.
Fourth, in seeking to bring down repressive and authoritarian regimes, there are viable alternatives to violent insurrection—as the mass uprisings in Tunisia and Egypt remind us. Since the mid-1980s the number of autocracies in the world has declined by some 70 percent. Yet strikingly few of these transitions were the result of violent insurgencies; still fewer resulted from foreign military intervention. A substantial number, however, were brought about by unarmed “people power” movements—and without any help from external powers. Such movements offer a promising alternative to violent insurgencies whose success rates have been declining.
In the two decades since the Cold War ended, a dynamic, inchoate, rarely efficient, but nonetheless quite effective system of global security governance has emerged. Its central focus is civil war in the developing world, and it comprises a loose network of international organizations—most importantly the UN and the World Bank—plus national governments and NGOs, plus informal clusters of like-minded states—like the various “Friends of the Secretary-General” groups—that share core values and objectives and are created to support peace negotiations and peacebuilding missions.
This is not a mode of governance that eschews the use of the military—indeed peacekeeping is central to its peacebuilding policy. But its major security objectives—conflict prevention, peacemaking, and post-conflict peacebuilding—are pursued primarily by non-military means.
The evolution of this nascent security system has been, and remains, messy, disputatious, and—as Rwanda and Darfur remind us—prone to tragic failures. But the security initiatives that have been pursued have been a major driver of the dramatic post–Cold War decline in armed conflict. This is no mean achievement.
 Figure 1 only counts conflicts in which a government is one of the warring parties and is either fighting another government (an international conflict) or a non-state armed group (intrastate conflict). Conflicts in which a government is not one of the warring parties—intercommunal conflicts, or those between rival rebel groups or warlords, are not counted. There are however relatively few of these conflicts and they are far less deadly on average than conflicts in which a state is one of the warring parties. Conflicts are defined here as violent contestations that result in least 25 battle deaths a year. Battle deaths include so-called “collateral dammage”—i.e., civilians caught in the crossfire.
 Geoffrey Blainey, The Causes of War, Third Edition, New York, Free Press, 1988. p. 3.
 Kenneth Waltz, “Peace, Stability, and Nuclear Weapons,” Institute on Global Conflict and Cooperation,
Policy Paper No. 15, University of California, Berkeley, August 1995, 9.
 Executive Summary, Economic Freedom of the World, 2005, Washington D.C., Cato Institute, 2005. http://www.cato.org/pubs/efw/efw2005/efw2005es.pdf. p. 3.
 Ann Hironaka, Neverending Wars: the International Community, Weak States, and the Perpetuation of Civil War, Cambridge, Harvard University Press, 2005. p 124.
 Monty Marshall, “Global Trends in Democratization,” Center for Systemic Peace, http://www.systemicpeace.org/polity/polity4.htm. p.17.
 See, Kurt Schock, Unarmed Insurrections: People Power Movements in Nondemocracies, Minneapolis, University of Minnesota Press, 2005.