Evolution or Invention?

Given the different definitions of war, it is not surprising that there is no general agreement about the causes of war and conflict. Nevertheless, different strands of thought on the origins of war can be highlighted. One is that violent conflict is an evolutionary trait to eliminate potential competitors. According to Lawrence Keeley, 90% to 95% of known societies throughout history<span class="span"><span id=hint class="box-source">have been involved</span><div class="popover">Source:<br><br><div>Keeley, L. H. War Before Civilization: the Myth of the Peaceful Savage. Oxford University Press, 1996.</div></div></span>in war. Another strand is that war was ‘invented’ as humans developed into increasingly larger social collectives. For example, in 1940, Margaret Mead wrote an article called ‘Warfare Is Only an Invention — Not a Biological Necessity.’ According to this way of thinking, if war is an invention then it can also end, like dueling in the nineteenth century.

Power Struggles

In addition to these broad strands, there are multiple theories about the origins of war. One of the earliest historians of war, Thucydides,<span class="span"><span id=hint class="box-source">wrote</span><div class="popover">Source:<br><br><div>Thucydides. History of the Peloponnesian War.</div></div></span>about the wars between Athens and Sparta between 431 and 404 BCE. He argued that war is about power; in this case, that Spartan fears of growing Athenian power made war inevitable. The long and continuing influence of this idea is well reflected in the 2017 book by Graham Allison, in which he<span class="span"><span id=hint class="box-source">argues</span><div class="popover">Source:<br><br><div>Allison, G. Destined For War: Can America and China Escape Thucydides's Trap?. The National Interest, 2017.</div></div></span>that “China and the US are currently on a collision course for war”, because China’s rising power threatens America’s hegemonic status. The term ‘Thucydides’ Trap’ was coined by Allison to suggest that the power struggle between America and China might reflect the disastrous struggle between Athens and Sparta two and a half thousand years ago. While this idea has attracted much media attention, numerous writers have questioned whether the term is either useful or accurate in helping to understand the complexities of great power relations . 

Some influential explanations of the causes of war have come from a broad school of analysis known as realism. For realists, power is the primary factor that shapes international outcomes. The dominant source of power is the state, which sees other states as threats or potential threats. Without an overarching constraining power (such as a world government), states are bound to fight. This view is clearly reflected in the title of Colin Gray’s 2005 book called Another Bloody Century. 

Kenneth Waltz, an influential realist scholar, developed a framework for studying war and international behavior in Man, the State and War (1959). Through this framework, the causes of war could be analyzed in three categories or levels:

• Individual level theories — These include the ambitions, misperceptions, biases, and cognitive limitations of humans as individuals and in groups. Waltz was critical of theories which focused on human nature, noting that “Human nature may in some sense have been the cause of war in 1914, but by the same token it was the cause of peace in 1910.”

• State level theories — Within this level, the causes of war are the results of the domestic characters of states, for example, whether they are warlike states. Waltz argued that these theories miss the fact that states do not operate in a vacuum but are heavily impacted by the international system. 

• Systemic level theories — This, for Waltz, is the more complete level of analysis. The focus is on the international system, which allows states to behave according to how much power they have. Waltz wrote that “wars occur because there is nothing to prevent them”. The international system is characterized by anarchy, which is a ‘permissive’ condition for war as there is no overarching international body with the power to prevent states going to war. 

The Complexity of Conflict

This approach has been influential for many analysts in thinking about war, but inevitably there are also many critics. Azar Gat, for example,<span class="span"><span id=hint class="box-source">argues</span><div class="popover">Source:<br><br><div>Gat, A. War in Human Civilization. Oxford University Press, 2008.</div></div></span>that war is much more complex than this and that “…these ‘levels’ are necessary but insufficient causes for war and the whole cannot be broken into pieces”.

Power may be a factor, even a significant factor, in the outbreak of war, but it is by no means the only factor. Scholars are still arguing about why the First World War began and the current conflict between Russia and Ukraine appears to be about much more than power relations. No single account or explanation can fully explain the complex interactions of events, motives, actions, and decisions that result in war.

Nationalism and War?

The word ‘nationalism’ covers an increasing range of ideas and interpretations. According to the Merriam Webster dictionary, nationalism exalts “one nation above all others…[promoting] its culture and interests as opposed to those of other nations.” 

Much has been written on the possible links between nationalism and war. Growing nationalism in European states is cited as one of the main factors for the outbreak of war in 1914 (the others are increased militarism — leading to more powerful armies and navies and the wish to use them; imperial rivalry — fuelled primarily by the imperialist expansions of German and Britain; and competition for power and influence). The forces of nationalism unleashed by the French Revolution of 1789, together with the wars that followed, had profound effects on many states. “By the end of the nineteenth century”,<span class="span"><span id=hint class="box-source">wrote</span><div class="popover">Source:<br><br><div>Howard, M. War and the Nation-State. Daedalus, 1979.</div></div></span>Michael Howard, “…nationalism had spread throughout Europe. By the second half of the twentieth it had circled the globe. And it was a movement whose demands were total”. Nationalism, moreover, became “characterized by militarism”, such that “Britain was Trafalgar…” as the naval victory by Nelson became representative of Britain’s view of itself.

Michael Mann does not share this view,<span class="span"><span id=hint class="box-source">arguing</span><div class="popover">Source:<br><br><div>Mann, M. The Sources of Social Power Volume 3: Global Empires and Revolution, 1890–1945. Cambridge University Press, 2012.</div></div></span>that the main reason war broke out was because of the decisions made by various privileged government leaders: “Nationalism was not the problem. Organized labor, most peasant, and even most of the middle class were not warmongers…The nationalist and imperialist pressure groups that organized pro-war demonstrations were outnumbered before the war by larger antiwar protests. The people, however, were largely irrelevant to decision making. This was a war decided on by political and military elites…”.

Nationalism in the First World War and Beyond

The images of eager young men and women queuing in their many thousands to join up and fight in 1914 are, today, tragic reminders of the emotional power of nationalism. However, the immense shock of the First World War and the perceived waste of so many lives to a pointless cause led many in Europe and America to reject ideas such as king and country. Nationalism retreated and new forces — Fascism and Communism — spread, which would later stamp their own mark on the wars of the 1930s and 1940s in particular. The Paris Peace Conference of 1919 had tried to reorder the international system to prevent such a war happening again. Empires were dissolved, new borders were created, and new states established. New institutions such as the League of Nations were attempts to bring international solutions to problems of war and peace, in the hope of managing nationalist passions. These efforts were not successful, with tragic consequences. As Margaret MacMillan concludes in her book Peacemakers — The Paris Peace Conference of 1919 and Its Attempt to End War (2002), “The peacemakers… grappled with huge and difficult questions. How can the irrational passions of nationalism or religion be contained before they do more damage? How can we outlaw war? We are still asking these questions”.

Does war serve any beneficial purpose? While many wars seem to leave nothing but death and destruction in their wake, war can also lead to positive change. The eighteenth century German philosopher Immanuel Kant<span class="span"><span id=hint class="box-source">believed</span><div class="popover">Source:<br><br><div>Coker, C. Why War?. Hurst Publishers, 2021.</div></div></span>we were hard wired to be violent because “We have programmed into us a desire for honour, power and status”, which have driven us to progress. Indeed, some would argue that significant, long-term change to the international system can only happen through war. B. H. Liddell Hart, the influential British historian and strategist (1895-1970),<span class="span"><span id=hint class="box-source">wrote</span><div class="popover">Source:<br><br><div>Liddell Hart, B. H. Sherman: Soldier, Realist, American. Da Capo Press, 1993.</div></div></span>that “The legitimate object of war is a more perfect peace”. 

For Ian Morris, war has had various positive effects,<span class="span"><span id=hint class="box-source">stating</span><div class="popover">Source:<br><br><div>Morris, I. War! What Is It Good For?: Conflict and the Progress of Civilization from Primates to Robots. Profile Books, 2015.</div></div></span>, “…war has been good for something: over the long run, it has made humanity safer and richer…War has produced bigger societies, ruled by stronger governments, which have imposed peace and created conditions for prosperity”.

In The Great Leveller: Violence and the History of Inequality, Walter Scheidel argues that, historically, the events that truly reduce inequality have been mass mobilization warfare, revolution, state collapse, and plague, which he calls the ‘Four Horsemen’. Although he believes that for inequality to reduce, wars and revolutions need to be total (such as WW1 and WW2 and the communist revolutions in Russia and China). In lower scale wars and revolutions, the elites tend to benefit most. “There does not seem”, he writes, “to be an easy way to vote, regulate, or teach our way to significantly greater equality”.

Though there is much conflicting and often unreliable data on how many years of peace there have been in recorded history, the evidence points to very few. Since 1946, the overall number of conflicts has risen, while the overall deaths from conflicts have<span class="span"><span id=hint class="box-source">declined markedly.</span><div class="popover">Source:<br><br><div>Roser, M. et al. War and Peace. Our World in Data.</div></div></span>This is because the majority of these conflicts have been civil conflicts within states rather than war between states.

Steven Pinker’s influential book The Better Angels of Our Nature: Why Violence Has Declined (2011) presents a lot of data showing significant declines in all forms of violence over time and within countries. Despite this, he argues, our overall perceptions of violence do not reflect this decline, partly perhaps because modern communications fill our screens with seemingly endless examples of violence globally. Pinker’s analysis has led to much divided opinion. An early challenge came from Pasquale Cirillo and Nassim Taleb who<span class="span"><span id=hint class="box-source">strongly criticized</span><div class="popover">Source:<br><br><div>Cirillo, P. and Taleb, N. The Decline of Violent Conflicts: What Do the Data Really Say?. The Nobel Foundation, 2016.</div></div></span>the data and analysis. “…Pinker’s severe mistake”, they wrote, “is one of standard naïve empiricism – basically mistaking data (actually the absence of data) for evidence and building his theory of why violence has dropped without even ascertaining whether violence did indeed drop”.

Liddell Hart’s idea of a “more perfect peace” has proven to be an elusive goal. In 1919, in a speech at Verdun, the French Prime Minister Georges Clemenceau said, “It is easier to make war than peace.” Clemenceau was one of the principal architects at the Paris Peace Conference after World War One. 

Efforts to Prevent War

In the long history of warfare, the idea that peace could and should be achieved through political means has only been established within the past 200 or so years. Even leading up to 1914, war was seen as a normal and acceptable way of settling international differences. 

Following perceptions of wasteful slaughter during the First World War, a key aim of the Paris Peace Conference of 1919 was to prevent such a war occurring again. According to the British diplomat<span class="span"><span id=hint class="box-source">Harold Nicholson</span><div class="popover">Source:<br><br><div>Nicolson, H. G. Peacemaking 1919. Faber and Faber, 2013.</div></div></span>, “We were journeying to Paris, not merely to liquidate the war, but to found a new order in Europe. We were preparing not Peace only, but Eternal Peace”.

Michael Howard<span class="span"><span id=hint class="box-source">argued</span><div class="popover">Source:<br><br><div>Howard, M. The Invention of Peace: Reflections on War and International Order. Yale University Press, 2001.</div></div></span>that peace had to be invented, unlike war. “Peace”, he wrote, “is not an order natural to mankind: it is artificial, intricate and highly volatile”. Following the Napoleonic Wars (1793–1814), peace movements were established in the US and UK. The London Peace Society was formed in 1816 to promote permanent, universal peace. The Society convened the first International Peace Congress in London in 1843. In the mid-1850s, William Cobden, British politician and advocate of free trade, focused his energies on campaigning for peace. He believed strongly that free trade was a powerful force for establishing peace and preventing war.

In 1889, the Austrian novelist Bertha von Suttner published an anti-war novel called Lay Down Your Arms. Though both author and book are now largely forgotten, Suttner won the Nobel Peace Prize in 1905 and, according to<span class="span"><span id=hint class="box-source">Samuel Moyn</span><div class="popover">Source:<br><br><div>Moyn, S. Humane: How the United States Abandoned Peace and Reinvented War. Farrar, Straus and Giroux, 2021.</div></div></span>, “Before World War 1, no document of Western civilization did more to …[argue] for an end to endless war into a mainstream cause”. In Europe, the peace movement was further energized by Norman Angell’s The Great Illusion (1909), which sold millions of copies and was translated into 25 languages. According to Angell, the economic costs of war far outweighed the benefits and, thus, a European war was unlikely to start. Angell also won the Nobel Peace Prize in 1933. Living through two world wars, he lost much of his earlier idealism, coming to see the benefits of collective security for maintaining peace and supporting the establishment of NATO in 1949.

The Kellogg–Briand Pact: An Attempt to Outlaw War

Almost 10 years after the conference to end all wars, an attempt was made in 1928 to outlaw war in a treaty signed by 15 nations that came to be known as the Kellogg–Briand Pact. Within a year, most states in the world had signed up, renouncing their right to go to war. In 1935, Italy invaded Ethiopia and, in 1939, Germany invaded Poland, triggering the Second World War. One interpretation of these events is that it is impossible, perhaps even foolish, to attempt to ban war legally. 

As argued in The Internationalists And Their Plan to Outlaw War by Oona Hathaway and Scott Shapiro (2017), another interpretation is that the Kellogg–Briand Pact led to gradual but influential changes in international law, which significantly reduced interstate war. A major step was Article 2(4) of the UN Charter (October 1945), which prohibits states from resorting to the “threat or use of force” against another state. According to Hathaway and Shapiro, there have also been other developments, including the revolution in human rights. The book ends with a quote from Briand in 1928: “Peace is proclaimed: that is well, that is much. But it still remains necessary to organize it… That is to be the work of tomorrow”.

That work has still to be done. Moyn<span class="span"><span id=hint class="box-source">argues</span><div class="popover">Source:<br><br><div>Moyn, S. Humane: How the United States Abandoned Peace and Reinvented War. Farrar, Straus and Giroux, 2021.</div></div></span>in his book that the attempts to make war more humane through international law and more distant, such as through drone strikes, have helped to weaken the peace movement. As a result, today we live in an age of ‘forever wars’, which do not directly impact on the lives of most citizens of the attacking states, but lead to the continuing export of death and destruction.