War Is on the Rocks


War, or at least interstate war, is on the rocks. Developed countries have managed to avoid major conflicts with one another now for 75 years — perhaps the longest such hiatus in history. And in recent decades, less developed countries have followed suit. Indeed, over the last 30 years, there have been only four interstate wars, conventionally defined as conflicts with at least 1,000 battle-related deaths per year. One was waged by Ethiopia and Eritrea in the last years of the 20th century. One was waged last year by Azerbaijan and Amenia. And the others were the brief regime-toppling invasions by the United States of Afghanistan and Iraq that then devolved into extended counterinsurgency — or counter-occupation — conflicts.

If this condition continues to hold, it would be one of the most important developments in human history. All the more remarkable, the shift away from interstate war appears to be the result not of changing geopolitical circumstances but of changing attitudes toward war itself. It took two world wars, but aversion to interstate war eventually conquered Europe and now is on track to envelop the world. Civil wars may continue, and states may still grapple with each other at less lethal levels. But the time may have come for us to accept the fact that interstate war is merely an idea, an institution that is scarcely required by international society. As Yale’s Robert Dahl pointed out decades ago, “Most social scientists have turned away from the historical movement of ideas.” But in doing so, they may “leave out an important explanatory variable.”

A Culture of Interstate Peace

The European continent took the lead in the turn away from war. It was once the most warlike of continents — Thomas Jefferson, for example, proclaimed it to be “an arena of gladiators.” But since 1945, Europe has been free from substantial interstate warfare for probably the longest period of time since the continent was invented as a concept some 2,500 years ago. Writing in 1986, historian Evan Luard suggested that this was “perhaps the single most striking discontinuity that the history of warfare has anywhere provided.”



That discontinuity has continued, and it demands explanation. In my opinion, it primarily reflects the fact that over the course of the 20th century, a significant shift has taken place in attitudes toward interstate war. Before World War I, it was common, even routine, for serious writers, analysts, and politicians in Europe and North America to exalt war between states as beautiful, honorable, holy, sublime, heroic, ennobling, natural, virtuous, glorious, cleansing, manly, necessary, and progressive. At the same time, they declared peace to be debasing, trivial, empty, bovine, and rotten, characterized by crass materialism, artistic decline, repellant effeminacy, rampant selfishness, base immorality, petrifying stagnation, sordid frivolity, degrading cowardice, and corrupting boredom. After 1918, however, such claims were scarcely ever voiced.

It is not completely clear why World War I was such a turning point. There had been plenty of massively destructive wars before, often fought to the point of complete annihilation. Many of these were equally futile, stupid, and disgusting as well — mud, leaches, and dysentery were not invented in 1914. One possibility is that World War I was the first war in history to be preceded by substantial, organized agitation against interstate war. At times, people in this growing movement even thought it was on the verge of success. In 1911, for example, the distinguished British historian G. P. Gooch concluded hopefully, “We can now look forward with something like confidence to the time when war between civilized nations will be considered as antiquated as the duel.” However, this was still very much a minority movement, and it was largely drowned out by those who exalted war. Nonetheless, its gadfly arguments were persistent and unavoidable, and this may well have helped Europeans and North Americans to look at the institution of international war in a new way after the massive conflict of 1914 to 1918. At any rate, within half a decade, opponents of interstate war, once a derided minority, became a decided majority.

There were, however, two countries that, in different ways, did not get the message. One was Japan — a less developed but increasingly powerful state that had barely participated in World War I. Many people there could still enthuse over war in a manner than had largely vanished in Europe. It took a cataclysmic war for Japan to learn the lessons almost all Europeans had garnered from World War I. The second country was Germany. In contrast to Japan, however, it appears that only one person there was willing to embrace international war, but he proved to be crucial. As military historian John Keegan argues, “Only one European really wanted war: Adolf Hitler.” For historian Gerhard Weinberg, Hitler was “the one man able, willing, and even eager to lead Germany and drag the world into war,” while William Manchester observes that the war Hitler started was one “he alone wanted.” Indeed, Hitler was successful in the 1930s in part because no one else on the continent could imagine that anyone could possibly be so stupid as to desire war. That is to say, but for Hitler, the massive war there would likely never have come about.

World War I, then, shattered what some have called the “war-like spirit” in Europe and North America. It made large majorities there into unapologetic peace-mongers — at least with regard to interstate war. World War II, it appears, reinforced that lesson in those places, probably quite unnecessarily, and it converted the previously militaristic Japanese in Asia. And of late, the aversion to interstate war has been embraced even more widely in international society.

Among the many consequences of this is a changing perception of power itself. “All historians agree,” observed Leo Tolstoy in 1869, “that states express their conflicts in wars and that as a direct result of greater or lesser success in war the political strength of states and nations increases or decreases.” That notion, it appears, has become passé. Prestige now comes not from prowess in armed conflict but from economic progress, maintaining a stable and productive society, and, for many, putting on a good Olympics, sending a rocket to the moon, or successfully managing a pandemic. The post-war success enjoyed by Germany and Japan provides further evidence that the culture of peace has transformed the very idea of “power” in international affairs.

Consider the Counterarguments 

While the European Union is regularly credited with preserving European peace, the causation is not necessarily so clear-cut. Focusing on the shift in attitudes toward interstate war suggests that the institutions that have been fabricated in Europe should be seen as the consequence of the post-war aversion to interstate war, not its cause. For example, it was the deep desire for international peace that was the driving force for the creation of the coal and steel community between France and Germany, an arrangement that eventually evolved into the European Union. France and Germany were once extremely good at getting into wars with each other, but since 1945 there seems to have been no one in either country who wanted to resume their venerable tradition. If interstate peace is the general expectation, international trade is facilitated, and it becomes much easier to create institutions and rules that reinforce that peace. But it is desire for peace that facilitates these conventions, not the other way around. Rules of the road may keep people from being killed in traffic. But we created them because we did not want to be killed.

It also seems likely that the long Cold War peace in which the chief contestants avoided direct war with each other would have taken place even without the invention of nuclear weapons. In fact, because of the contestants’ aversion to getting into any sort of direct international war, there was nothing for those weapons to deter. Most notably, Moscow clearly had no interest in starting, or even planning, a major war, whether nuclear or not. In 1977, George F. Kennan argued that the Soviet Union had “no desire for any major war … Plotting an attack on Western Europe would be … the last thing that would come into its head.” And late in the Cold War, he said, “I have never believed that they have seen it as in their interests to overrun Western Europe militarily, or that they would have launched an attack on that region generally even if the so-called nuclear deterrent had not existed.”

After the Cold War, a great amount of documentary evidence became available, confirming these assertions. As Robert Jervis notes, “The Soviet archives have yet to reveal any serious plans for unprovoked aggression against Western Europe, not to mention a first strike against the United States.” And, after researching those archives, historian Vojtech Mastny concludes that “All Warsaw Pact scenarios presumed a war started by NATO.” Thus, “The strategy of nuclear deterrence [was] irrelevant to deterring a major war that the enemy did not wish to launch in the first place.” As a top Soviet war planner put it in a 1992 interview, “We never had a single thought of a first strike against the [United States]. The doctrine was always very clear: we will always respond, but never initiate.”

It could be argued, of course, that this perspective stemmed from American deterrence policy. However, the burden of proof is on those making this argument. They would have to demonstrate that the Soviets ever had the desire to risk a conflict that might even slightly resemble the catastrophe they had just endured in World War II. Moreover, they were under the spell of a theory that said they would eventually come to rule the world in a historically inevitable process to which they would contribute merely by safely inspiring and supporting like-minded revolutionaries abroad.

Developed countries have certainly engaged in other kinds of armed conflict since 1945. There have been civil wars in the developed world and colonial wars continued until the impelling institution was abandoned. Although the Cold War, contrary to many fears, never led to World War III, it still had bloody consequences. Communist ideology explicitly advocated class warfare and what it called “revolutionary civil wars” around the world. Some of these revolutionary conflicts resulted in massive death not only by warfare but, as in China and Cambodia, by social policy and execution. Moreover, the response from the United States and others to these revolutions led to armed interventions and proxy wars that, in places like Korea, Vietnam, and Afghanistan, proved far more costly to the locals than to the interveners.

However, these wars should not be thought of as an export of the violence Europe was avoiding. As historian Paul Thomas Chamberlin stresses, the central dynamic in this process was one in which “local revolutionary forces” attached themselves to an international movement rather than one in which they were created by it. Most civil wars have been generated by local conditions, including especially incompetent or venal governments rather than by global rivalries.

Continued Contestation

Although interstate war may be on the rocks, states still compete with each other by other means, ones that are less lethal at least to them. Indeed, because of the decline of international war, states may have come to feel freer to engage in behavior that might once have been taken to be casus belli.

Thus, although civil wars have declined in frequency since the 1980s, outside countries have become, if anything, more willing to tinker in them, sometimes supporting insurgent or terrorist groups, sometimes threatened regimes. This can result in something resembling proxy wars. As noted earlier, the phenomenon was common during the Cold War, and it was seen later in the complex and disastrous civil war that took place in the Democratic Republic of the Congo at the end of the last century. More recently, foreign interveners in Syria and Yemen have likely contributed to extending the length and lethality of civil conflicts there. Whether the grim results of such interventions will reduce their frequency in the future remains to be seen.

Moreover, as Georgia State University’s Dan Altman has pointed out, there have been scores of armed border conflicts between states since 1945, often resulting in the seizure of territory. However, these activities have scarcely ever led to full-fledged war. Indeed, to avoid that outcome, they have increasingly been waged over territory that is unpopulated and ungarrisoned. This phenomenon, says Altman, “is a symptom of war’s decline, not its cause.” Indeed, except for Iraq’s invasion of Kuwait in 1990 there have been no instances of one United Nations member invading another and seeking to incorporate all of its territory — something that had been standard practice for millennia.

In the last few decades, states have often engaged in coercive economic diplomacy, particularly by imposing sanctions on other countries. Although these have not led to actual warfare, they have sometimes had considerable human costs, most notably in Iraq in the 1990s and currently in Iran and North Korea. As Richard Hanania has noted, sanctions have a miserable record at exacting substantial policy change. However, they will likely continue to be applied because, unlike actual warfare, they usually inflict little pain on the sanctioning countries while giving the politically desirable, and perhaps sanctimonious, impression that the sanctioners are “doing something” to punish an offending regime.

States have also very frequently attempted covert regime change in other counties. The United States, for example, has indulged in election interference for decades. But regime change hasn’t proved much more effective than economic sanctions. In her study of U.S. regime change efforts since World War II, Boston College’s Lindsey O’Rourke concludes that the majority have failed, while those that succeed often led to new regimes that were much the same as their predecessors. Moreover, the clear successes have mostly occurred in countries such as France, Italy, and Japan in which desirable change would likely have happened anyway.

More recently, cyber attacks have emerged as something of a poor man’s substitute for war. Dubbed “likewar” by some writers, these efforts, unlike actual war, have scarcely ever inflicted physical damage and have yet to kill anybody. However, the opportunities for espionage and propaganda propagation have been extended, and cyber attacks have succeeded in causing temporary inconvenience, creating employment for geeks to counter them, and, like international terrorism, stoking a vast alarmist literature. The phenomenon is unlikely to go away.

And, of course, there will continue to be international incidents like the poaching of fish — a practice that has been common ever since humans and fish were invented, whichever came second.


Interstate war appears to be in pronounced decline. This seems to have come about primarily because attitudes toward it have changed, much as the ancient and once-formidable institution of formal slavery became discredited and then obsolete. The emergence of a culture of interstate peace has come about not only without the service of cherubs, doves, and choirs of angels, but also without changing human nature. And it came about without creating an effective world government, without modifying the nature of the state, without spreading democracy and prosperity to every corner of the earth, without picking more competent political leaders, and without doing much of anything about nuclear weapons.



John Mueller is a political scientist at Ohio State University and a Senior Fellow at the Cato Institute. His book, The Stupidity of War: American Foreign Policy and the Case for Complacency, has just been published by Cambridge University Press.

Image: Wikicommons (Photo by AlfvanBeem)