Earlier this year I was on holiday in Corsica and happened to wander into the church of a tiny hamlet in the hills where I found a memorial to the dead from World War I. Out of a population that can have been no more than 150, eight young men, bearing among them only three last names, had died in that conflict. Such lists can be found all over Europe, in great cities and in small villages. Similar memorials are spread around the globe, for the Great War, as it was known prior to 1940, also drew soldiers from Asia, Africa, and North America.

… if we can see past our blinders and take note of the telling parallels between then and now, the ways in which our world resembles that of a hundred years ago, history does give us valuable warnings.

World War I still haunts us, partly because of the sheer scale of the carnage—10 million combatants killed and many more wounded. Countless civilians lost their lives, too, whether through military action, starvation, or disease. Whole empires were destroyed and societies brutalized.

But there’s another reason the war continues to haunt us: we still cannot agree why it happened. Was it caused by the overweening ambitions of some of the men in power at the time? Kaiser Wilhelm II and his ministers, for example, wanted a greater Germany with a global reach, so they challenged the naval supremacy of Great Britain. Or does the explanation lie in competing ideologies? National rivalries? Or in the sheer and seemingly unstoppable momentum of militarism? As an arms race accelerated, generals and admirals made plans that became ever more aggressive as well as rigid. Did that make an explosion inevitable?

July 1916: During the Battle of the Somme, British soldiers from the Cheshire Regiment occupy a German trench near Ovillers-la-Boisselle in northern France.
Wikimedia Commons/Imperial War Museum

Or would it never have happened had a random event in an Austro-Hungarian backwater not lit the fuse? In the second year of the conflagration that engulfed most of Europe a bitter joke made the rounds: “Have you seen today’s headline? ‘Archduke Found Alive: War a Mistake.’” That is the most dispiriting explanation of all—that the war was simply a blunder that could have been avoided.

June 28, 1914: Serbian nationalist Gavrilo Princip is captured in Sarajevo after assassinating Archduke Franz Ferdinand of Austria, along with his wife, Sophie.
Wikimedia Commons

The search for explanations began almost as soon as the guns opened fire in the summer of 1914 and has never stopped. Scholars have combed through archives from Belgrade to Berlin looking for the causes. An estimated 32,000 articles, treatises, and books on World War I have been published in English alone. So when a British publisher took me out to lunch on a lovely spring day in Oxford five years ago and asked me if I would like to try my hand at one of history’s greatest puzzles, my first reaction was a firm no. Yet afterward I could not stop thinking about this question that has haunted so many. In the end I succumbed. The result is yet another book, my own effort to understand what happened a century ago and why.

It was not just academic curiosity that drove me, but a sense of urgency as well. If we cannot determine how one of the most momentous conflicts in history happened, how can we hope to avoid another such catastrophe in the future?

Just look at the actual and potential conflicts that dominate the news today. The Middle East, made up largely of countries that received their present borders as a consequence of World War I, is but one of many areas around the globe that is in turmoil, and has been for decades. Now there’s a civil war in Syria, which has raised the spectre of a wider conflict in the region while also troubling relations among the major powers and testing their diplomatic skills. The Bashar al-Assad regime’s use of poison gas—a weapon first deployed in the trench warfare of 1914, then outlawed because world opinion viewed it as barbaric—nearly precipitated American airstrikes. Commentary on these developments was filled with references to the guns of that long-ago August. Just as policymakers then discovered they had started something they could not stop, so this past summer we feared that such airstrikes might lead to a wider and more long-lasting conflict than anyone in President Barack Obama’s administration could foresee.

During World War I: French police officers wearing gas masks patrol the streets of Paris on bicycle.
Prisma/UIG via Getty Images

2013: U.N. chemical weapons experts examine samples from an alleged chemical weapons attack in a neighborhood of Damascus, Syria.
Reuters/Mohamed Abdullah

The one-hundredth anniversary of 1914 should make us reflect anew on our vulnerability to human error, sudden catastrophes, and sheer accident. So we have good reason to glance over our shoulders even as we look ahead. History, said Mark Twain, never repeats itself but it rhymes. The past cannot provide us with clear blueprints for how to act, for it offers such a multitude of lessons that it leaves us free to pick and choose among them to suit our own political and ideological inclinations. Still, if we can see past our blinders and take note of the telling parallels between then and now, the ways in which our world resembles that of a hundred years ago, history does give us valuable warnings.

Though the era just before World War I, with its gas lighting and its horse-drawn carriages, seems very far off and quaint, it is similar in many ways—often unsettlingly so—to ours, as a look below the surface reveals. The decades leading up to 1914 were, like our own time, a period of dramatic shifts and upheavals, which those who experienced them thought of as unprecedented in speed and scale. The use of electricity to light streets and homes had become widespread; Einstein was developing his general theory of relativity; radical new ideas like psychoanalysis were finding a following; and the roots of the predatory ideologies of fascism and Soviet communism were taking hold.

July 1915: The battleship Missouri steams through the Panama Canal, one of three U.S. warships traversing the canal together that month.
Keystone-France/Gamma-Keystone via Getty Images

ca. 2010: The Korean-built Corte Real container ship, one of the largest in the fleet of CMA CGM, a French-based maritime shipping company.
Wikimedia Commons

Globalization—which we tend to think of as a modern phenomenon, created by the spread of international businesses and investment, the growth of the Internet, and the widespread migration of peoples—was also characteristic of that era. Made possible by many of the changes that were taking place at the time, it meant that even remote parts of the world were being linked by new means of transport, from railways to steamships, and by new means of communication, including the telephone, telegraph, and wireless. Then, as now, there was a huge expansion in global trade and investment. And then as now waves of immigrants were finding their way to foreign lands—Indians to the Caribbean and Africa, Japanese and Chinese to North America, and millions of Europeans to the New World and the Antipodes.

Taken together, all these changes were widely seen, particularly in Europe and America, as clear evidence of humanity’s progress, suggesting to many that Europeans, at least, were becoming too interconnected and too civilized to resort to war as a means of settling disputes. The growth of international law, the Hague disarmament conferences of 1899 and 1907, and the increasing use of arbitration between nations (of the 300 arbitrations between 1794 and 1914 more than half occurred after 1890) lulled Europeans into the comforting belief that they had moved beyond savagery.

July 2005: Supporters of British National Party chairman Nick Griffin wave placards outside Leeds Crown court where Griffin faced race-hate charges.
AFP Photo/Steve Parkin/Getty Images

The fact that there had been an extraordinary period of general peace since 1815, when the Napoleonic wars ended, further reinforced this illusion, as did the idea that the interdependence of the countries of the world was so great that they could never afford to go to war again. This was the argument made by Norman Angell, a small, frail, and intense Englishman who had knocked around the world as everything from a pig farmer to a cowboy in the American West before he found his calling as a popular journalist. National economies were bound so tightly together, he maintained in his book, The Great Illusion, that war, far from profiting anyone, would ruin everyone. Moreover, in a view widely shared by bankers and economists at the time, a large-scale war could not last very long because there would be no way of paying for it (though we now know that societies have, when they choose, huge resources they can tap for destructive purposes). A sensational best-seller after it was published in Britain in 1909 and in the United States the following year, its title—meant to make the point that it was an illusion to believe there was anything to be gained by taking up arms—took on a cruel and unintended irony only a few short years later.

Ralph Norman Angell (1872-1967): British lecturer, journalist, author, politician. Wikimedia CommonsWhat Angell and others failed to see was the downside of interdependence. In Europe a hundred years ago the landowning classes saw their prosperity undermined by cheap agricultural imports from abroad and their dominance over much of society undercut by a rising middle class and a new urban plutocracy. As a result, many of the old upper classes flocked to conservative, even reactionary, political movements. In the cities, artisans and small shopkeepers whose services were no longer needed were also drawn to radical right-wing movements. Anti-Semitism flourished as Jews were made the scapegoat for the march of capitalism and the modern world.

The world is witnessing unsettling parallels today. Across Europe and North America, radical right-wing movements like the British National Party and the Tea Party provide outlets for the frustration and fears that many feel as the world changes around them and the jobs and security they had counted on disappear. Certain immigrants—such as Muslims—come to stand in as the enemy in some communities.

Globalization can also have the paradoxical effect of fostering intense localism and nativism, frightening people into taking refuge in the comfort of small, like-minded groups. One of the unexpected results of the Internet, for example, is how it can narrow horizons so that users seek out only those whose views echo their own and avoid websites that might challenge their assumptions.

Leon Czolgosz, assassin of President William McKinley in October 1901.
Wikimedia Commons

John Walker Lindh, aka the "American Taliban," convicted in 2002 of charges related to aiding the Taliban and al Qaeda.
Reuters/Handout

Globalization also makes possible the widespread transmission of radical ideologies and the bringing together of fanatics who will stop at nothing in their quest for the perfect society. In the period before World War I, anarchists and revolutionary socialists across Europe and North America read the same works and had the same aim: to overthrow the existing social order. The young Serbs who assassinated Archduke Ferdinand of Austria at Sarajevo were inspired by Nietzsche and Bakunin, just as their Russian and French counterparts were. Terrorists from Calcutta to Buffalo imitated each other as they hurled bombs onto the floors of stock exchanges, blew up railway lines, and stabbed and shot those they saw as oppressors, whether the Empress Elizabeth of Austria-Hungary or U.S. President William McKinley. Today new technologies and social media platforms provide new rallying points for fanatics, enabling them to spread their messages even more rapidly and to even wider audiences around the globe. Often they claim divine inspiration. All of the world’s major religions—Buddhism, Hinduism, Judaism, Christianity, and Islam—have produced their share of terrorists prepared to commit murder and mayhem in their name. Thus we see the young offspring of Muslim parents from Pakistan and Bangladesh, even those born or raised in the United Kingdom and North America, going off to make common cause with Syrian rebels, the Taliban in Afghanistan, or one of the branches of al Qaeda in North Africa or Yemen, despite sharing almost nothing—culturally or ethnically—with those whose cause they have taken up.

It is tempting—and sobering—to compare today's relationship between China and the U.S. with that between Germany and England a century ago. Now, as then, the march of globalization has lulled us into a false sense of safety.

May 1915: After the German navy's sinking of the British ocean liner Lusitania, in which 1,195 lost their lives, enraged Londoners attack a German immigrant's tobacco shop.
Mary Evans Picture Library

October 2013: "Get Out," say members of a far-right group as they demonstrate in Lyon, France, next to a camp of illegal migrants, most from Albania.
Reuters/Robert Pratta

At the national level, globalization can heighten rivalries and fears between countries one might otherwise expect to be friends. One hundred years ago, on the eve of World War I, Britain, the world’s greatest naval power, and Germany, the world’s greatest land power, were each other’s largest trading partners. British children played with toys, including lead soldiers, made in Germany, and Covent Garden resounded with the voices of German singers performing German operas. Moreover, the two nations shared a religion—the majority in both was Protestant—and family ties, right up to their respective monarchs. But all that did not translate into friendship. Quite the contrary. With Germany cutting into Britain’s traditional markets and vying with it for colonies and power, the British felt threatened. As early as 1896, a best-selling British pamphlet, Made in Germany, painted an ominous picture: “A gigantic commercial State is arising to menace our prosperity, and contend with us for the trade of the world.”

ca. 1906: Workers in the paint shop at the Daimler Motors Corporation near Stuttgart work on the chassis of a Mercedes-Simplex.
Daimler AG

June 2013: Zhejiang Geely Holding Group Chairman Li Shufu at a Volvo assembly line in Chengdu, Sichuan province. The Chinese company bought the Swedish automaker in 2010.
Reuters/Jason Lee

Many Germans held reciprocal views. Germany, they said, was due its place in the sun—and an empire on which the sun would never set—but Britain and the British navy were standing in its way. When Kaiser Wilhelm and his naval secretary Admiral Alfred von Tirpitz decided to build a deep-water navy to challenge British naval supremacy, the unease in Britain about Germany’s growing commercial and military power turned into something close to panic.

Erskine Childers’ 1903 best-seller, The Riddle of the Sands, described a German invasion plot, stirring British fears about their lack of military preparedness. Rumours spread, fanned by the new mass circulation newspapers, of German guns buried under London in preparation for war, and 50,000 waiters in British restaurants who were really German soldiers. For its part, the German government seriously feared a pre-emptive attack on its fleet by the British navy, and the German public had its own share of invasion scares. On several occasions before 1914 parents in coastal towns kept their children home from school in anticipation of an imminent landing by British marines.

Before 1915: Imperial German Navy submarine U-14, sunk in the North Sea in 1915.
Wikimedia Commons

Cooler heads on both sides hoped to wind down the increasingly expensive naval race, but in each country, public opinion, then a new and incalculable factor in the making of policy, pushed in the direction of hostility rather than friendship. Even the blood ties between the German and the British royal families, which might have been expected to ameliorate these mutual antipathies, did quite the opposite. Kaiser Wilhelm, that strange and erratic ruler, hated his uncle King Edward VII, “the arch-intriguer and mischief-maker in Europe,” who, in turn, dismissed his nephew as a bully and a show-off.

It is tempting—and sobering—to compare today’s relationship between China and the U.S. with that between Germany and England a century ago. Now, as then, the march of globalization has lulled us into a false sense of safety. Countries that have McDonald’s, we are told, will never fight each other. Or as President George W. Bush put it when he issued his National Security Strategy in 2002, the spread of democracy and free trade across the world is the surest guarantee of international stability and peace.

Yet the extraordinary growth in trade and investment between China and the U.S. since the 1980s has not served to allay mutual suspicions. Far from it. As China’s investment in the U.S. increases, especially in sensitive sectors such as electronics and biotechnology, so does public apprehension that the Chinese are acquiring information that will put them in a position to threaten American security. For their part, the Chinese complain that the U.S. treats them as a second-rate power and, while objecting to the continuing American support for Taiwan, they seem dedicated to backing North Korea, no matter how great the provocations of that maverick state. At a time when the two countries are competing for markets, resources, and influence from the Caribbean to Central Asia, China has become increasingly ready to translate its economic strength into military power. Increased Chinese military spending and the build-up of its naval capacity suggest to many American strategists that China intends to challenge the U.S. as a Pacific power, and we are now seeing an arms race between the two countries in that region. The Wall Street Journal has published authoritative reports that the Pentagon is preparing war plans against China—just in case.

Will popular feeling, fanned and inflamed by the mass media in the same way that it was in the early years of the 20th century, make these hostilities even more difficult to control? Today the speed of communications puts greater than ever pressure on governments to respond to crises, and to do so quickly, often before they have time to formulate a measured response.

We are witnessing, as much as the world of 1914, shifts in the international power structure, with emerging powers challenging the established ones. Just as national rivalries led to mutual suspicions between Britain and the newly ascendant Germany before 1914, the same is happening between the U.S. and China now, and also between China and Japan. And now as then, public opinion can make it difficult for statesmen to maneuver and defuse hostilities. Although political leaders like to think they can use popular feeling for their own ends, they often find that it can be unpredictable. In the 1990s, the Chinese Communist Party launched what it called a Patriotic Education Campaign to inculcate the young with nationalist sentiments, but the leaders lost control of their followers.

A propaganda campaign against Japan inspired mobs to sack Japanese businesses and offices. For their part the Japanese, who have attempted to lower the temperature in the past—apologizing for Japanese crimes during World War II for example—are less willing to do so today. The new prime minister, Shinzo Abe, plays to a growing and vociferous Japanese nationalism. He has announced that he intends to revise the constitution so that he can increase Japan’s military spending, and during this year’s election campaign he made a point of visiting one of the obscure and largely uninhabited islands which is in dispute with China in the East China Sea. As a result of the current standoff and occasional naval muscle flexing there and in the South China Sea over these islands, attitudes in both countries are hardening, limiting the options for their leaders. And there is potential for conflict between China and two of its other neighbors—Vietnam and Malaysia—as well.

Germania, a wall painting by Philipp Veit in 1848 in St. Paul's Church for the Frankfurt National Assembly.
Wikimedia Commons

November 2004: Japanese sailors during an annual military review at Asaka, in suburban Tokyo.
AFP/Yoshikazu Tsuno/Getty Images

Once lines are drawn between nations, it can be difficult to reach across them. The U.S. and Iran have had a difficult relationship ever since the Shah was overthrown in 1979 (and indeed it was not all that easy even during his reign). The events of subsequent years—including the hostage taking, the American shooting down of an Iranian airliner, Iran’s quest for its own bomb, and the U.S.’s attempt to block it, all to the accompaniment of much angry rhetoric—have kept them far apart. When one side does make conciliatory noises, as Iran’s new President Hassan Rouhani has done recently, memories of past wrongs perpetuate suspicions about present intentions, complicating such attempts.

Misreadings and manipulations of history can also fuel national grievances and bring war closer. In the Europe of a hundred years ago the growth of nationalist feeling—encouraged from above but rising from the grass roots where historians, linguists, and folklorists were busy creating stories of ancient and eternal enmities—did much to cause ill will among nations who might otherwise have been friends. Teutons had always been menaced by Slavs from the east, or so learned German professors assured their audiences before 1914, and therefore peace between Germany and Russia must be impossible. In the Balkans, competing nationalisms, each with its own story of triumphs and defeats, drove apart peoples such as Serbs, Albanians, and Bulgars who had lived in relative harmony for centuries—and are still driving them apart today.

"Serbia must die!" reads this Austrian propaganda caricature, after the assassination of Archduke Ferdinand. An Austrian hand is crushing a Serb terrorist.
Wikimedia Commons

Often, as in families, the most bitter of these sectarian quarrels arise among those most similar to each other. Witness the religious and ethnic wars in the former Yugoslavia, or the spreading civil wars in the Middle East, and indeed throughout the Muslim world, where the doctrinal differences between Sunni and Shia are hardening into ideological and political conflict. What Freud called the “narcissism of small differences” can lead to violence and death—a danger amplified if the greater powers choose to intervene as protectors of groups outside their own borders who share a religious or ethnic identity with them. Here too we can see ominous parallels between present and past. Before World War I Serbia financed and armed Serbs within the Austrian Empire, while both Russia and Austria stirred up the peoples along each other’s borders. And we all know how Hitler used the existence of German minorities in Poland and Czechoslovakia to dismember those countries. Today Saudi Arabia backs Sunnis—and Sunni-majority states—around the world, while Iran has made itself the protector of the Shia, funding radical movements such as Hezbollah.

FIRST COUSINS AT WAR

George was first cousins with both Wilhelm and Nicholas. All of them were descendants of King George II of England, making them also fifth cousins. Wilhelm II image: Wikimedia Commons- Reichard und Lindner, publisher: Gustav Liersch & Co.; George V image: Wikimedia Commons- Bain News Service, publisher; Nicholas II image: Wikimedia Commons- Author unknown.

Enmities between lesser powers can have unexpected and far-reaching consequences when outside powers choose sides to promote their own interests. In the years before World War I, Russia chose to become Serbia's protector, both in the name of Pan-Slavism and also to extend its influence down to Istanbul and the straits leading out of the Black Sea. When Austria-Hungary declared war on Serbia, Germany, feeling it had to support Austria-Hungary, declared war on Russia, even at the risk of a world war. Because of alliances and friendships developed over the previous decades, France and then Britain were also drawn in to fight alongside Russia. Thus the war turned almost at once into a wider one.

1914: In this Punch cartoon, "The Power Behind," a Serbian cockerel stands proudly while its protector the Russian bear hides behind a rock. The Austrian eagle says, "I don't quite like his attitude. Somebody must be backing him."
Punch Limited

May 2012: Supporters of Syrian President Bashar al-Assad in Damascus holds signs with images of al-Assad and Russian President Vladimir Putin.
Reuters/Khaled al-Hariri

While history does not repeat itself precisely, the Middle East today bears a worrying resemblance to the Balkans then. A similar mix of toxic nationalisms threatens to draw in outside powers as the U.S., Turkey, Russia, and Iran all look to protect their interests and their clients. Will Russia feel it has to support Syria, the same way it once felt it had to support its client Serbia, and Germany felt it had to support Austria-Hungary? We must hope that Russia will have more control over the Damascus government than it had over Serbia in 1914. But so far international efforts to defuse the Syria crisis have been complicated by Russia's investment in the survival of the Assad regime in the face of the threat of U.S. military action.

Great powers often face the dilemma that their very support for smaller ones encourages their clients to be reckless. And their clients often slip the leading strings of their patrons. The U.S. has funnelled huge amounts of money and equipment to Israel and Pakistan, for example, as China has done to North Korea, yet that has not given either the Americans or the Chinese commensurate influence over the policies of those countries. Israel, while hugely dependent on America, has sometimes tried to push Washington into taking pre-emptive military action. And Pakistan gave sanctuary to America's global enemy number one, Osama bin Laden.

Before 1914 the great powers talked of their honor. Today U.S. Secretary of State John Kerry refers to America's credibility or prestige. It amounts to much the same thing.

Moreover, alliances and friendships forged for defensive reasons or mutual advantage can look quite different from other perspectives. Before 1914 German statesmen assumed that the military pact between France and Russia was really designed to destroy Germany. Today Pakistan feels threatened by the links between India and Afghanistan, while the U.S. tends to see a challenge in China's increasing influence in Central Asia, Africa, and Latin America.

Making matters worse, patron nations are reluctant to abandon their clients, no matter how far they have run amok and no matter what dangers they themselves are being led into, because to do so incurs the risk of making the greater power appear weak and indecisive. Before 1914 the great powers talked of their honor. Today U.S. Secretary of State John Kerry refers to America's credibility or prestige. It amounts to much the same thing.

Like our predecessors a century ago, we assume that large-scale, all-out war is something we no longer do. To be sure, we are aware that people are still being killed in conflicts around the world, many of them civil, ethnic, or religious, as in Syria and Iraq today. But since 1945 the world has seen far fewer wars between states and it has survived dozens of relatively minor conflicts, from Korea to the Congo, with the number of casualties dwarfed by those sustained in the two world wars. The Iran-Iraq war of the 1980s, with perhaps as many as 500,000 dead, and the protracted war in the Great Lakes region of Africa stand out as the main exceptions in recent years.

In short, we have grown accustomed to peace as the normal state of affairs. We expect that the international community will deal with conflicts when they arise, and that they will be short-lived and easily containable. But this is not necessarily true. The Socialist leader Jean Jaurès, a man of great wisdom who tried unsuccessfully to staunch the rise of militarism in France in the early years of the 20th century, understood this very well. “Europe has been afflicted by so many crises for so many years,” he said on the eve of World War I, and “it has been put dangerously to the test so many times without war breaking out, that it has almost ceased to believe in the threat and is watching the further development of the interminable Balkan conflict with decreased attention and reduced disquiet.”

"Congress of Vienna," an 1857 engraving by Jean-Baptiste Isabey depicting the leaders signing the Treaty of Paris.
Wikimedia Commons (etching after painting by Jean Baptiste Isabey)

September 2013: Members of the UN Security Council vote unanimously to approve a resolution eradicating Syria's chemical arsenal at a Security Council meeting in New York.
Reuters/Adrees Latif

The international community as a whole has created institutions dedicated to defusing conflict and forcing aggressors to back down—and they can be effective for long periods of time. The Concert of Europe, that collection of the Great Powers, kept the peace for much of the century after 1815. Yet we should keep in mind that it did not last forever. Institutions as much as people get old and tired. Although they gave it lip service, the Great Powers eventually ceased to believe in the idea of effective and concerted action to avoid conflict, and the world order began to break down—with disastrous consequences.

In 1908, when Austria-Hungary enraged Serbia by annexing Bosnia, where some 44 percent of the population were Serbs, Germany forced Russia, Serbia’s protector, to back down. Tsar Nicholas II wrote to his mother: “It is quite true that the form and method of Germany’s action—I mean towards us—has simply been brutal and we won’t forget it.” He didn’t. And when the crisis of 1914 erupted, Tsar Nicholas, a weak man who had until then preferred peace to war, was determined, like most of his ministers, that this time Russia would not give in to pressure from Germany or its ally Austria-Hungary. In 1911 Italy defied an unwritten agreement among the powers to maintain the integrity of the Ottoman Empire and seized Tripoli and Cyrenaica, the two North African provinces which later became Libya. The Powers made disapproving noises but did nothing. In the Balkans Wars of 1912 and 1913 the Powers managed to impose a settlement of sorts, but increasingly they saw themselves as being on opposing sides. By the time of the crisis of 1914, the kaiser and his ministers greeted British suggestions that the Great Powers work together to bring a peaceful solution with derision.

We expect that the international community will deal with conflicts when they arise, and that they will be short-lived and easily containable. But this is not necessarily true.

Are we seeing a similar weakening of the international order today? The United Nations, which might be seen as a successor to the Concert of Europe, has at times intervened successfully to maintain the peace or restore it after war has broken out. But in the Security Council today, Russia and China habitually vote against U.N. interventions, which they see as a cover for promoting Western interests. In the case of Syria, Assad has so far been able to defy international opinion and kill his own people because he has the Russians as well as the Iranians with him. President Vladimir Putin and his foreign minister dismissed the charges that Assad has used poison gas as “absurd.”

The pre-war arms race was actually a good thing, a British diplomat, Sir Francis Bertie, told his king, George V: “The best guarantee of peace between the Great Powers is that they are all afraid of each other.” However, he was wrong to put his faith in that early version of the theory of mutually assured destruction. Too many of those who commanded Europe’s armies were only too ready to go to war, either because they thought the time was advantageous or they believed they could win. But in the Cold War, when the U.S. and Soviet Union possessed almost all of the world’s nuclear weapons, mutually assured destruction did work. Both sides recognized that atomic and hydrogen bombs were so destructive that they had in effect rendered themselves unusable. If the two countries had waged all-out war, the thermonuclear Armageddon would have left no winners anywhere in the world, only losers. Can we assume that deterrence will continue to work today?

1907: The battleship HMS Dreadnought, flagship of Britain's Home Fleet, had revolutionary armaments and steam propulsion that made it the fastest such ship in the world, and part of the pre-WWI arms race.
U.S. Naval Historical Center via Wikimedia Commons

March 2007: Nuclear-capable missile Shaheen II is driven with its launcher during the Pakistan National Day parade in Islamabad. India and Pakistan are engaged in an arms race of their own.
Reuters/Mian Khursheed

We have entered a new and potentially perilous era. There are now nine countries with nuclear arsenals, including Pakistan, a fractious if not failing state, and North Korea, which has proved itself as reckless as it is repressive. Depending on whether Iran gets the bomb, numerous other states—including Japan perhaps— are likely to exercise their own nuclear options. That would make for a very dangerous world indeed, which could lead to a recreation of the kind of tinderbox that exploded in the Balkans a hundred years ago—only this time with mushroom clouds.

Like the world of 1914, we are living through changes in the nature of war whose significance we are only starting to grasp.

But even if all nations were to agree that nuclear war simply does not make sense, there are drawbacks and dangers to the wars being waged with conventional weapons, which many of our military leaders fail to understand. Like the world of 1914, we are living through changes in the nature of war whose significance we are only starting to grasp.

A hundred years ago, most military planners and the civilian governments who watched from the sidelines got the nature of the coming war catastrophically wrong. The great advances of Europe’s science and technology and the increasing output of its factories during its long period of peace had made going on the attack much more costly to human life. The killing zone—the area that attacking soldiers had to cross in the face of deadly enemy fire—had expanded hugely from 100 yards in the Napoleonic wars to over 1,000 yards by 1914. And the rifles, machine guns, and artillery they faced were firing faster, more accurately, and with more deadly explosives. There was plenty of evidence from the smaller wars fought before 1914—the American Civil War, the Franco-Prussian War of 1870-71, and the Russo-Japanese War of 1904-5—about what this would mean on the battlefield. Soldiers attacking, no matter how brave, would suffer horrific losses, while defenders sat in the relative security of their trenches, behind sandbags and barbed wire. Yet the best brains in Europe’s general staffs refused to face the new reality, explaining away or ignoring the uncomfortable facts, just as today many choose to ignore the overwhelming scientific evidence of global warming. The European powers went into war in 1914 with plans that, without exception, were predicated on an offensive strategy. As a British major general said in 1914, “The defensive is never an acceptable role to the Briton, and he makes little or no study of it.” The British—and the soldiers of many other nations—paid a high price for that willful blindness.

June 1916: Australian soldiers in a breastwork trench, constructed from sandbags, near Armentières in northern France.
Wikimedia Commons/Imperial War Museum

October 2012: Drone operators fly an MQ-9 Reaper training mission from a ground control station at Holloman Air Force Base, New Mexico.
Reuters/Airman 1st Class Michael Shoemaker/USAF/Handout

A comparable fallacy in our own time is that because of our advanced technology, we can deliver quick, focused, and overpowering military actions—“surgical strikes,” “shock and awe”—resulting in conflicts that will be short and limited in their impact, and victories that will be decisive. Challenging the faith that such low-cost victories are possible, Major General H.R. McMaster, the commanding officer at Fort Benning, Georgia, and something of an iconoclast, recently wrote in the New York Times that many of the assumptions that had guided the American military before 9/11 and up to and through the early years of the wars in Iraq and Afghanistan were wishful thinking. To view “successful military operations as ends in themselves, rather than just one instrument of power that must be coordinated with others to achieve, and sustain, political goals” is, he believes, a mistake. The wars in Iraq and Afghanistan, he said, were not just matters of military strength but “contests of will.” Fighting them without an understanding of the social, economic, and historical factors involved will doom us to “the pipe dream of easy war,” as the title of his piece puts it.

May 2003: U.S. President George W. Bush addressing the nation about progress in the Iraq War aboard the nuclear aircraft carrier USS Abraham Lincoln. Getty Images/AFP/Stephen Jaffe

And indeed there do not seem to be any easy wars. Increasingly we are seeing asymmetrical wars between well-armed, organized forces on one side and low-level insurgencies on the other, which can span not just a region but a continent or even the globe, and where there is not one enemy but a shifting coalition of local warlords, religious warriors, and other interested parties. Think of Afghanistan or Syria, where local and international players are mingled and what constitutes victory is difficult to define. In such wars those ordering military action must consider not just the combatants on the ground but the elusive yet critical factor of public opinion. Thanks to social media, every air strike, artillery shell, and cloud of poison gas that hits civilian targets is now filmed and tweeted around the world.

The ultimate goal of military action must be to achieve political ends, whether to win over local opinion by providing security, to bring competing parties to the table to negotiate, or to persuade the world at large of the rightness of its actions. Those who believe in “precision strikes” and their potential to deliver meaningful victories must understand that or else we, like those who preceded us a hundred years ago, will continue to fight the wrong kinds of battles.

With different leadership World War I might have been avoided. Europe in 1914 needed a Bismarck or a Churchill with the strength of character to stand up to pressure and the capacity to see the large strategic picture. Instead the key powers had weak, divided, or distracted leaders. Kaiser Wilhelm had come down on the side of peace in earlier crises, but he knew that officers in his beloved army referred to him contemptuously as Wilhelm the Timid. Thus, in 1914, when his generals were urging him that the time had come for a preventive war on Russia, he was afraid of appearing weak. Just after the assassination of the heir to the throne in Sarajevo, when Germany issued the infamous “blank cheque” promising to back Austria-Hungary come what may, Wilhelm said—repeatedly—to a close friend: “This time I shall not give in.” His chancellor, Theobald von Bethmann Hollweg, devastated by the recent death of his wife, accepted the prospect of war with glum resignation. And in Austria-Hungary itself, the war party led by the generals now had the upper hand, for the assassination of the archduke had ironically removed the one man who might have resisted the drift to war. As it was, the old and ailing emperor, Franz Josef I, was left alone to face the hawks.

On the other side, Russia, like Germany, had a weak ruler with too much power—and too great a fear of appearing weak. Tsar Nicholas hesitated but in the end gave way to his own war party and ordered the general mobilization that made war with Germany inevitable. The clinching argument, apparently, came from one of his ministers, who told him he could not save his throne or the lives of himself and his family unless he showed himself to be resolute against Russia’s enemies.

Uniform swap in 1905: Emperor Wilhelm II of Germany (l) in Russian uniform, and Tsar Nicholas II of Russia (r) in Prussian uniform.
German Federal Archive via Wikimedia Commons

Herbert Henry Asquith, 1st Earl of Oxford and Asquith, served as the Liberal Prime Minister of the United Kingdom from 1908 to 1916. Wikimedia CommonsThe British government, which might have acted decisively enough early in the crisis to have deterred Germany, was preoccupied by the prospect of a civil war over Ireland. And the prime minister, Herbert Asquith, who was also distracted by a new love affair, allowed the slide to war to gather momentum, even as Sir Edward Grey, the foreign secretary, floated ineffectual proposals for negotiations. In Washington President Woodrow Wilson watched the events with dismay from his place at the side of his dying wife, but at first he saw no good reason why the U.S. should intervene in a European quarrel.

Contrast the behavior of the men in power in 1914 with that of John F. Kennedy nearly five decades later, during the Cuban Missile Crisis, when the world faced an even greater threat. The young and relatively untried U.S. president was urged by virtually his entire top military leadership as well as many of the civilians in his administration to confront the Soviet Union vigorously, up to the point of invading Cuba and so risking an all-out nuclear war. Standing up to them, he opted instead for negotiations with Moscow and, in the end, preserved the peace. It was perhaps fortunate that he had just read Barbara Tuchman’s great The Guns of August and was very mindful of the ways nations can blunder into war.

October 2013: The U.S. Capitol looms behind a sign on the National Mall reminding visitors of the closures to all national parks due to the federal government shutdown in Washington. Reuters/Kevin Lamarque

Today the American president is facing a series of politicians in China who, like those in Germany a century ago, are deeply concerned that their nation be taken seriously. In Putin he must deal with a Russian nationalist who is both wilier and stronger than the unfortunate Tsar Nicholas. Barack Obama, like Woodrow Wilson, is a great orator, capable of laying out his vision of the world and inspiring Americans. But like Wilson at the end of the 1914-18 war, Obama is dealing with a partisan and uncooperative Congress. Perhaps even more worrying, he may be in a position similar to Asquith’s in 1914, presiding over a country so divided internally that it is unwilling or unable to play an active and constructive role in the world.

Britain, which once played an international leadership role during the 19th and the first part of the 20th centuries, in the end found the demands too great and the costs too high. After World War II the British people were no longer willing and the British economy no longer capable of sustaining such a role.

The U.S. has so far been prepared to act as the guarantor of international stability, but may not be willing—or able—to do so indefinitely. Over a century ago, at a time when it was well-launched on its rise to world power status and in the process of translating its huge and growing economic strength into military and foreign policy, it began to assume the mantle of leadership. Teddy Roosevelt and Woodrow Wilson, though they were two very different types of men, shared the feeling that the U.S. had a moral obligation to the world. “We have become a great nation,” Roosevelt said, “and we must behave as beseems a people with such responsibilities.” Since then, there have been times when isolationist sentiments have threatened this commitment, but the U.S. has for the most part remained deeply engaged in world affairs, through World War II, to the effort to contain Soviet aggression during the Cold War, and to the present global war on terrorism. With the collapse of the Soviet Union and its empire at the end of the 1980s, the U.S., perhaps without reflecting, continued to act as the world’s hegemon, assuming responsibilities that ranged from stabilizing the international economy to ensuring security. The long agony of Bosnia finally came to an end in 1995 when American pressure in combination with NATO military action persuaded the Serbs to enter into the Dayton Agreement. And although America’s actions in Iraq and Libya were certainly not met with universal acclaim, even in the U.S. itself, Saddam Hussein and Moammar Gaddafi had few friends and many enemies by the time they met their ends at American hands.

The U.S. has so far been prepared to act as the guarantor of international stability, but may not be willing—or able—to do so indefinitely.

ca. 1917: British monarch King George V(l), with General John Joseph Pershing, commander-in-chief of the American expeditionary Force in Europe. Hulton Archive/Getty Images

April 2013: U.S. Marines participate in a joint operation with South Korean forces. The two Koreas have been technically in a state of war since a truce that ended their 1950-53 conflict. Reuters/Lee Jae-Won

Today, however, the U.S., while still the strongest power in the world, is not as powerful as it once was. It has suffered military setbacks in Iraq and Afghanistan, and has had difficulty finding allies who will stand by it, as the current Syrian crisis demonstrates. Uncomfortably aware that they have few reliable friends and many potential enemies, the Americans are now considering a return to a more isolationist policy.

May 2012: Supporters of the political and religious party Jamat-e-Islami hold a banner while taking part in an anti-American rally in Karachi, Pakistan. The banner written in Urdu reads "unacceptable." Reuters/Athar Hussain

Is the U.S. now reaching the end of its tether, as Britain did before it? If it retreats even partially from its global role, which powers will dominate the international order, and what will that mean for the prospects of world peace?

It is difficult to guess what might come next. Russia may dream of its Soviet past when it was a superpower, but with a chaotic economy and a declining population its ambitions far outrun its capacities. China is a rising power but its preoccupations are likely to be focused on Asia. Further afield it will concentrate, as it is doing at present, on securing the resources it needs for its economy, while probably being reluctant to intervene in far-off conflicts where it has little at stake. The European Union talks of a world role but so far has shown little inclination to develop its military resources, and its internal divisions make it increasingly difficult for Brussels to get agreement on foreign policy. The countries in the BRICS group—Brazil, Russia, India, China, and South Africa—are joined together more in theory than reality. The hope of a coalition of democracies, from Asia to America, willing to intervene in the name of humanitarianism or international stability, reminds me of the old story of the mice and the cat—who is going to be first to put the bell around the animal’s neck? As for public opinion, the citizenry within individual countries, preoccupied with domestic issues, has become increasingly unwilling to fund or take part in foreign adventures.

Margaret MacMillan

is a professor of international history at Oxford University where she is warden of St. Antony’s College. She is also a history professor at the University of Toronto. MacMillan is an acclaimed author, whose titles include  The War that Ended Peace: The Road to 1914;  Dangerous Games: The Uses and Abuses of History;  Women of the Raj: The Mothers, Wives, and Daughters of the British Empire in India; and the multiple-award-winning  Paris 1919: Six Months that Changed the World, among others. MacMillan is a Fellow of the Royal Society of Literature and is a member of numerous editorial boards, including First World War Studies. 

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It may take a moment of real danger to force the major powers of this new world order to come together in coalitions able and willing to act. Action, if it does come, may be too little and too late, and the price we all pay for that delay may well be high. Instead of muddling along from one crisis to another, now is the time to think again about those dreadful lessons of a century ago in the hope that our leaders, with our encouragement, will think about how they can work together to build a stable international order.

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