There was considerable shock and disgust at the broadcasts of the Daesh movement in 2015, as it murdered prisoners, beheaded hostages, detonated truck bombs among civilians using suicide attacks and, in perhaps the nadir of its actions, burned alive a captured Jordanian pilot. The bulletins, mostly released online, seemed to bear little relevance to the movement’s strategic objective of building an Islamic state and their behaviour seemed to indulge in violent excesses and atrocities for their own sake. While terror is an acknowledged technique of warfare, and although the true nature of war is an unrestricted, limitless life-or-death struggle, the global reaction to Islamic State forces was that they had plumbed new depths of depravity. Formerly, atrocities had usually been concealed, or were accidentally recorded, but here was a movement celebrating and glorying in its murderous activities, actively seeking to acquire as much exposure on the world’s media as possible.

Daesh was all the more shocking because it was using the tools of modernity – the internet, social media and the latest weapons technology – to wage an unmodern, barbarous form of warfare, in an age where, for a variety of reasons, the states of the developed world believed they had civilised war through institutions, laws and other instruments. The dissonance between modern tools and unmodern actions was disconcerting, the more so when a significant number of young people from Western countries chose to travel to join Islamic State.

The nature of war is visceral. It is, in essence, constituted of killing, subjugation and coercion. It is about morale: pacifying, breaking, or sustaining the will to fight and resist. It is also about rationalism, in that its participants fight for a cause and constantly calibrate their cost-benefit assessments. War possesses a degree of theatre in that it is enacted in particular arenas, before an audience of peers. Its rituals are periodically reinforced, renewed or reworked, particularly when new forces with different levels of development, or widely divergent cultures, encounter each other. There is also the human dimension, where participants impose their own limits on the killing and coercion. Individuals choose, on occasion, not to take a life; armed groups refuse to engage and even states may opt for limited objectives to avoid the annihilation or enslavement of an enemy. While there are instincts to fight or flee for self-preservation, there are other contradictory reactions in war: to obey, to resist, to provide succour and to protect.

This essay reflects on the origins of industrial war and on the debates that have surrounded the development of technology: on rationalism, bureaucracy, systemisation and professionalisation, which are associated with the rise of the West and the orthodox definition of modern war. First, it is important to acknowledge that modernity is a relative concept, as the concepts of both war and modernity are always changing. Furthermore, there are inconvenient episodes in the history of war that complicate the neat, linear picture of progress and modernity. Archaic armies, under the right circumstances, could still defeat modern armies. Forces that thought of themselves as modern were still capable of carrying out practices recognised as premodern. No one was quite sure where modernity began and by what criteria it should be measured. In the late 20th century, there was a strong focus on the ‘military revolution’ debate among early modern historians, concentrated on the question of timing: did the modern state emerge with its bureaucracies and then subsequently find it had the capital to raise gunpowder armies, or did the armies come first, pushing states into a modern dispensation? This debate gave way to ideas of evolution and a series of revolutions, not all of which were dependent on technological change, culminating in a revolution in military affairs.

Postmodern critics, inspired by philosophy in the arts, have raised some more profound and disturbing questions that can be applied to the idea of modernity in war. Their critique challenges the certainty of language and normative behaviours, showing how war disciplines individuals and groups. They point to the irony of the idea of ‘information age’ warfare, with its promises of greater insight through an abundance of data. What is most disturbing about a phenomenon like Islamic State is the reminder that much about war is unchanging and unmodern.

Michael Roberts’s 1956 article, ‘The Military Revolution, 1560–1660’, focused on Gustavus Adolphus and Sweden’s military reforms in the early modern period. His argument was taken up by other historians, notably Geoffrey Parker, to advance the idea that the gunpowder revolution rendered fortifications more vulnerable and thus also the state, which consequently necessitated large field armies. These armies required much greater sophistication in terms of administration, not least because gunpowder weapons required highly trained personnel and mobilisation was, therefore, even more demanding than the previous requirements for military engineers (for fortifications) and metal workers (for weapons and armour). The larger field armies also demanded more professionalised officers and non-commissioned officers. Roberts argued that drill assumed greater importance. The new drilled armies were modern, he argued, in that they were neither ‘the brute mass in the Swiss style, nor a collection of bellicose individuals in the feudal style’. Roberts concluded that Gustavus Adolphus stood ‘like a great divide separating medieval society from the modern world’.

Roberts associated turning points in history with the introduction of particular military technologies – such as the sword, the mounted warrior, the stirrup – and the scientific revolution. His selection of the mid-16th to the mid-17th century for his military revolution, drew criticism, not least because bayonets, railways and machine technologies were introduced later, while officers and non-commissioned officers both pre-dated and post-dated his revolutionary epoch. Moreover, while feudal fortifications were certainly affected by artillery, they had been in a constant process of evolution, and with the advent of more efficient mobile and siege cannon, fortifications moved quickly beyond the trace italienne to the fieldwork geometry of Vauban and, ultimately, a system of interlocking strongpoints in depth that emerged in the First World War.

Nevertheless, despite the critics, Roberts had identified a period of profound change and made some noteworthy observations. He argued that military revolutions had been accompanied by a predominance of mercenaries, which, taken in a wider context, might be rephrased today as a preponderance of privatised interests in warfare. In the information warfare revolution that is currently underway, it is striking that so much of the technological development is being led by private corporations and that non-state actors, like Islamic State, are exploiting its potential more rapidly than conventional armies.

Institutions also mattered to Roberts, who argued that the appalling loss of life and levels of destruction wrought by the wars of religion, not least the Thirty Years’ War, gave rise to a desire to regulate the excesses of unlimited war. There was agreement among state rulers that laws of war were desirable, but despite that Roberts believed the sheer power of financial organisation and applied science already pointed the way to the ‘abyss of the 20th century’.

In assessing modernity, we would do well to remember that history is contingent and not obedient to iron laws. Historian Jeremy Black has often warned us against assuming consistency and continuities with the benefit of retrospection. Nevertheless, Victor David Hanson posited that a ‘Western way of war’ emerged in the ancient world and suggested that certain forms of organisation and fighting were distinctive to Europeans thereafter. These included: advanced technology, superior discipline, an ability to adapt through an intellectual tradition of innovation, civic militarism (where the population broadly supported the military effort), an inclination towards seeking decisive battles, a preference for infantry, particularly those using bladed weapons rather than missiles, highly organised logistics with an economy geared to war and, finally, a moral opposition to aggression and violence that resulted in limited war, or justification and reasoning for war.

Modernity was, according to orthodoxy, the triumph of rationalism over the feral irrationality of the premodern. Science and mathematics, the logos of empiricism and reason, were driven by ballistics, fortress construction, accountancy in soldiers’ pay, the formulae for the correct ratios of constituent parts for gunpowder and taxation. Later, the regulation of citizens who could be mobilised into mass armies, or the sophisticated physics of nuclear weapons production, continued those early features of modernism. Systemisation appeared in military drilling, standard operating procedures, the banality of identifying the adversary by the faceless term ‘enemy’, doctrines, routines, codification and, ultimately, as we see today, coding. The logic of logos is to strip away the human factor in war and to seek the fastest means to acquire, engage and defeat a target; to ensure the most rapid communications, and to minimise the interference of ‘friction’ or the ‘fog’ of war.

This too has its limits. Armed forces across the modern world were uncomfortable with the logic of democratised mass armies and sought to preserve the elite, professional status of the premodern era. The officer corps, specialist military branches and the air arm all attempted to differentiate themselves from the mass of citizen-conscripts, emulating imagined cultures of the mounted, aristocratic warrior through their manners, accoutrements, language and clothing. Professionalism has become associated with highly trained, apolitical, disciplined and full-time military service to differentiate it from the armed retainers, bodyguards, or militia of the past and from the non-state actor or irregular of today. Professionals are subject to selection, promotion and compliant behaviours, some imposed and others self-generated. It is a caste that is schooled in academies or training establishments, skilled in staff work and other bureaucracy, educated through case studies and experienced through realistic battle inoculation or actual operations. Professionals provide important continuities and ‘institutional memory’ and are the result of increasing complexity in industrial societies. The advantage of professional military personnel is, as Max Weber argued of all bureaucracy, that of a centralised, impersonal and routinised authority, instead of amateurism, demagoguery and, therefore, certain failure.

The rise of the West, at least its military component, requires explanation beyond the concept of modernity. In many Asian and African campaigns, the Europeans were usually heavily outnumbered and were occasionally defeated. Motivated in part by a prestige that would not tolerate failure in colonial wars, the Europeans nevertheless pressed home their attacks with determination and sought a complete victory, often with permanent occupation, despite the odds against them. This differed from Asian and African ideas of military objectives, where often the aim was to compel the opponent to seek terms. European troops, and those they trained, were also prepared to take heavy casualties, their discipline, motivation and training overcame the instinctive desire for self-preservation. The Europeans were also well organised and able to sustain armies in the field permanently, whereas African or Asian hosts had to disperse to resume agriculture. The Europeans’ sea power gave them the chance to reinforce and supply forces thousands of miles from their homelands, while imperial colonies developed robust defences of their own.

It has been alleged that decisiveness is a hallmark of the modern. This assessment is constructed after the event and is too context-driven to be acceptable as a general principle of modernity. Take, for example, the contrast between the decisiveness and conviction of Crusader armies in the Levant in the 12th century with the decision to accept an armistice to conclude the fighting of the First World War. Decisiveness and ruthlessness seem less than convincing as necessary components of the idea of modernity, they sit uncomfortably alongside the equally problematic and apparently modern notions of total war, mass mobilisation and exterminism. Massed armies were required to absorb the casualties that more lethal and efficient weapons inflicted and which other forces had adopted as populations in Europe expanded, or their imperial frontiers grew more extensive. Yet the prospect of defeat or betrayal also drove convictions of totality – the mobilisation of the entire population to ensure its support and compliance in the French Revolution, for example. Lazare Carnot, the revolutionary Minister of War, called for guerre à l’outrance (all-out war). St Just, who presided over the Committee of Public Safety, demanded extermination for those who opposed the revolution.

Despite European efforts during the 19th century to avoid revolutionary people’s wars, by the 1890s, writers and analysts began to consider the idea of a war which would require the complete mobilisation of all national resources and a more ruthless prosecution of operations. Colmar von der Goltz, author of the best-selling Das Volk in Waffen (‘Nation in Arms’, 1883), predicted a ‘life or death struggle, the whole sum of the intelligence residing in nations will be employed for their mutual destruction’. Like many of his generation, von der Goltz argued that unlimited war was the inevitable consequence of biology, not ideology. He was, nevertheless, hopeful that the sheer destructive power of modern warfare would act as a deterrent – ‘and thus it comes to pass that battles generally are less bloody in proportion, as the engines of destruction have attained greater perfection’. His contemporary, Ivan Bloch, famously argued that war would become a stalemate, where the stresses on governments and economies would cause their collapse, not through results on the battlefield, but through revolutions. Carl von Clausewitz had long recognised the nature of war to be escalatory, absolute and extreme. To avoid the sort of scenario that Bloch later identified, Clausewitz urged his contemporaries to execute war with complete ruthlessness and a single focus from the outset and thus achieve a rapid victory. All effort, Clausewitz had urged, should be placed on concentrating force at the decisive point, so as to avoid the consequences of a long, bitter and protracted war.

Confronted with a powerful and indeed more numerous enemy in 1914, the French re-emphasised the moral component as offering the decisive edge in modern war. The army’s assessment was that: ‘we want an army which compensates numerical weakness with military quality… neither numbers nor miraculous machines will determine victory. This will go to soldiers with valour and ‘quality’, [that is] superior physical and moral endurance [and] offensive strength.’ The emphasis was to be on ‘a conquering state of mind’. Clausewitz had recognised this requirement arguing that what transformed 18th-century warfare was not the technology or organisation for war, but the psychology of the French Revolution, including the advent of nationalism.

The search for a moral edge, particularly among states that fear the future, has reappeared in the 20th and 21st centuries. The imperial Japanese emphasised the importance of individual conviction in waging war, but their forces earned a reputation for fanatical attacks, atrocities against Chinese civilians and Allied prisoners of war, and futile and irrational suicide air assaults by the kamikaze. The contemporary condemnation avoided analysis and labelled them simply ‘demonic’. Trying to reach an understanding of the phenomenon and why it existed at all requires an evaluation of the culture that was its context. Despite the abolition of the shogun (warlord) system of governance and the rapid modernisation of Japan from the mid-19th century, much of the old martial tradition remained embedded in Japanese life. The Zen code, a rigid form of militarism (itself derived from ideas of self-discipline in martial arts), was promoted through Japanese society by Nantembo and Zen monks: they advocated military values as a means to unify Japanese people and as a form of mental training, including utter obedience, self-deprivation and sacrifice, faith and comradeship, physical courage, and honour and atonement for shame, including the ‘humiliation’ of failure. There was also a distinctive view of death: it was an accepted fact, even in civilian life, that while death was not necessarily imminent, it was inevitable and therefore ought to be accepted quietly whatever the circumstances in which it was presented, summed up in the phrase: ‘Duty is weightier than a mountain, while death is lighter than a feather.’ In military circles, there was a strong culture of competition, urging personnel to excel against all others and to regard non-Japanese as inferior and therefore deserving of defeat. By the 1930s, this had been developed into the Senjinkun [soldier’s code].

The Senjinkun military code insisted that duty was elevated to a religious mission. The army, soldiers were told, was the means to bring about Hakko Ichi­U (world unity). Obedience to the emperor in this endeavour was vital because, they believed, he was a deity. His orders could not be disobeyed since they were religious instructions. Failure in battle meant letting down not just a soldier’s comrades, but also the country, the emperor and the divine mission, and the only way to atone for this, or prevent the situation getting worse, was to remove oneself from the mission honourably, that is by seppuku. The code insisted that enemies were to be treated courteously, but only if they had behaved honourably: those that surrendered had disgraced themselves. It was widely believed that soldiers who had fallen in battle were deified at the Yasakuni (Shinto shrine in Tokyo) and would be immediately transmitted to paradise, where they would enjoy lasting immortality among the gods. In training, the Japanese soldiers received religious instruction alongside their military skills. The religious Seishin Kyoiku was a set of values or virtues closely tied to the Senjinkun and these tenets were reinforced on battlefield tours, with slogans in mess halls, lectures and visits to museums. Soldiers were expected to cultivate a sense of inner power (the Ki’ai) which united the mind and the will to form an irresistible force. The logic of this training and culture was summed up in the desperate instruction of General Hidekei Tojo, who, in 1945, ordered his troops to ‘fight to extermination, or kill yourselves’.

The resonance with Islamic State and suicide terrorism is striking. It is a radical movement, seeking power from a position of weakness. It is desperate to avoid annihilation by invoking a stronger conviction in its fighters and supporters, in order to acquire a tactical edge. It utilises a unifying idea, a militant Islam, but it is content to distort the original principles of the faith in order to recreate an idealised past through any and all means. Like al-Qaeda, it is both a reaction to and utilisation of apparently modernist ideas. The ideology is clearly atavistic, seeking to create a polity governed by eighth century, premodern principles. It is utopian in the sense of wanting a single caliphate (in belief, but also, in territory) where such an entity lasted very briefly in history because of the profound divisions between the peoples of the Middle East. But their methods are modern in that they use the internet, social media, mobiles, laptops, digital cameras, UAVs (unmanned aerial vehicles) and online videos. Despite the modernity of means, their views are expressed with premodern, Manichean tropes. The alleged leader of Islamic State, al-Baghdadi, stated: ‘the world today has been divided into two camps and two trenches, with no third camp present: the camp of Islam and faith and the camp of kufr [disbelief] and hypocrisy.’ Such utterances remind one of Lenin, who made similar dichotomous deductions: ‘Since there can be no talk of an independent ideology formulated by the working masses themselves in the process of their movement, the only choice is – either bourgeois or socialist ideology. There is no middle course (for mankind has not created a ‘third’ ideology).’

What modernity in war also reiterated, if Roberts was correct in his assessment, were concepts of limited war, restraint and international institutions. The wars of religion had ended with recognition of state sovereignty and the independence of religious conviction within states, which was later extended to forms of individual toleration; this had increased the pressure to protect, through recognised international instruments, the status of non-combatants, the wounded and those made prisoner; it had even, despite the advent of nuclear weapons technology, established the norms of negotiation, safeguards and co-operation to avoid the consequences of ‘mutually-assured destruction’. Unlimited war had become almost unthinkable for modern states in possession of nuclear weapons’ technology, although, less reassuringly, some states argue that battlefield, tactical nuclear weapons might be used without risking escalation. What makes Islamic State so distinctly un-modern is their willingness to target civilians. Even at the height of the world wars, when air bombing campaigns were unleashed in Europe, efforts were made to reduce civilian losses, or to limit the targeting to workforces engaged in the war economy, although the inaccuracy of air bombing technologies made discrimination near impossible and total war incorporated vast numbers of civilians into citizen armies and labour forces into the war effort.

The attempt to discriminate, however imperfectly, continues to be the divide with genocide, where targeting civilians is deliberate, cynical, calculated and systematic. Al-Qaeda, Al-Nusra front and Islamic State leaders find justification in the complete annihilation of their enemies. For modern states, argued Martin van Creveld, nuclear weapons abolished all-out war and imposed restraint, but the convictions of militant jihadists suggest no such limits exist in their minds.

Rather than viewing modernity as progressive, postmodern critiques highlighted the absurdity of nuclear weapons, the destructiveness of industrial war and the lethal ideologies of the 20th century. They pointed to the disciplining of the body and mind to war, echoing Rousseau’s observation that man was not a willing participant in war, but had to be herded into it. Modern interpretations have converged with this perspective: the numbers prepared to volunteer for military service are relatively small; they require training to overcome the instincts of self-preservation and they require mental as much as physical conditioning. These observations are not entirely negative. Training creates bonding, which enables individuals to surmount the stresses of war. Moreover, if more digital means are used in the future to attack societies and individuals, playing on their sense of vulnerability at home, then processes which create social and group cohesion may assist in preventing terrorists from exploiting the atomising effect of a modern urbanised life.

Postmodernism also highlights the unpalatable absurdity of war in the information age. Despite the vast amount of ‘information’ – the billions of terabytes of data, winging their way around the globe, stored in cavernous databases, chips and motherboards – we are just as lacking in wisdom as our ancestors. Soldiers and policymakers in Iraq between 2003 and 2009, and Afghanistan between 2001 and 2014, were sometimes at a loss to know the causes of particular incidents, the decisions of their adversaries and the reactions of local civilians, even though the information was available in various forms (through local human interaction, digital surveillance and storage, or accumulated knowledge). Being able to marshal data and make it meaningful, or being able to interpret or analyse, is often lost in the maelstrom of accumulation and access. Being able to ask the right questions is as important, if not more so, than acquiring yet more data. Although heavily criticised for the admission, US Defense Secretary Donald Rumsfeld, famously acknowledged there were ‘unknown unknowns’. His observation that there are ‘known unknowns’ and, worse, ‘unknown knowns’ should surely have been the subject of more attention, because these, perhaps, could be tackled more successfully. The postmodernists would, of course, enjoy the irony that, in an information age, military campaigns are conducted without being able to grasp, understand or control information.

In the information age, there is a misplaced confidence in technology. In the Gulf War (1990–91), media personnel coined the phrase ‘CNN effect’ to describe the way in which dramatic footage from the nose-cameras of guided missiles, or moving images from nearby aircraft, caught the moment of detonation of ‘smart’ munitions. The diffusion of sources for footage and news coverage with the internet, YouTube and other social media, accompanied by more readily available technologies in the hands of citizens, has reduced the ability of militaries and states to concentrate and control information.

‘TV war’ has been replaced by the online video and this, in turn, has given rise to a form of conflict idealism not seen since the days of the International Brigades in the Spanish Civil War (1936–39). Impressionable young people, the digital natives who live their lives online and who are susceptible to the propaganda of Islamic State and other militants, find connection and compulsion sufficient to get them into the conflict zone. There, they encounter a new reality and embittered radicalisation takes place. In the latter, they share an experience with combat veterans from Western states, some of whom have volunteered to return to Iraq to fight alongside Kurdish irregulars against Islamic State. The transferability of identity, a premodern notion, coincides with modern means of communication, transport and conflict to produce the volunteerism of jihadism from the West and its reaction. The atomisation of modern society has reduced the sanction of established authorities, such as government, religious leaders and older adults. The collective has been reduced by an emphasis on the individual. War is a construction, not so much of the collective will and identity, as formerly, but now as a ritual among peers, where the desire to test oneself in the ultimate crucible of combat is fostered in the informational world, especially the video-game.

The character of war is constantly changing and so attributing a notion of modernity to war is necessarily problematic and probably short-lived, beyond the obvious idea that every age believes itself to be, in some way, modern. The character of modern industrial war was originally associated with developments in technology and organisation, which gave rise to a new bureaucratic state structure. These, in turn, were seen as the means to propel European armies across the globe and achieve hegemony. Modern war was also, rightly or wrongly, regarded as having a definitive end, a view fostered by the conclusive and dramatic termination of the Second World War. Modern war was thought of as sustained, high-intensity in nature, characterised by the technological supremacy of the major powers. Their information operations were conveyed to a well-defined and identifying audience, usually a national one. Conventional wars in the modern era are thought of as highly destructive, yet relatively short in duration. By contrast, post-industrial, or postmodern war, is deemed to have different characteristics. As a result of experiences since 1990, not least in fighting in the Democratic Republic of Congo, Colombia, in Iraq, Syria and Afghanistan, it is seen as unending, protracted and constant. Combat appears to have episodic intensity and major powers enjoy technological superiority, but are faced with periodic parity (as the extensive use of sniper fire and improvised explosive devices demonstrated in Iraq and Afghanistan). Information operations are conducted before a global, critical and sceptical audience. In the post-industrial era of war, there are further characteristics to be identified. The allegiance to states seems to be challenged by new, transnational identities, usually with distinct ideologies. Human-speed decisions appear to be confronted by greater reliance on computing power and algorithms and code. There is emerging global surveillance and the capabilities of states in this regard are also increasing. In the so-called information era, we may therefore expect more connected peoples, connected ideas, accelerated decisions and more surveillance.

Despite these changes, there are continuities. The drivers of war remain deeply human: fear, honour, interest, survival, uncertainty, a bellicose culture, domestic pressure, perceived injustice, reaction to incursion, ambition or opportunism, misunderstanding, or prejudice.

Modernity is a paradigmatic concept, but war doesn’t fit the notion very well. It is a heuristic device, but it has been challenged on the basis of its utility and veracity. In the early definitions, modern war was seen as the breakthrough that led to the formation of states. This in turn, meant that from the 18th century onwards the West possessed the ability to expand and influence the world: it had the weapons, finance, transport and organisation to project its power with increasing efficiency. Modern war was subsequently associated with industrial warfare, mass production, mass mobilisation and mass destruction. It was synonymous with technological developments, with rationalism, the growth of bureaucracy, systemisation and professionalisation. Notably, it was seen as part of the development of global mass communications.

In our own era, modern war has been challenged and analysts have sought to identify a postmodern character of war. Postmodernists were eager to criticise the confidence and hubris of power they saw in modern states, which had bequeathed a ‘colonial’ form of world hegemony, nuclear weapons, genocide and gross inequality. They problematised the rationalism of modernity and criticised its assumptions. While many of these philosophical devices were condemned, the critique as a whole was a useful reminder of the weaknesses of the ‘modern war’ logic. Information-age data-abundance did not produce any greater wisdom about war than the past. Indeed, critics argued it lulled analysts into a false sense of superiority.

Postmodernist critique highlighted the importance of power, coercion and discipline in war. It pointed out the contradictions of institutions that claimed to have regulated and limited war, yet which had spawned chemical warfare, the bombing of civilians and barbarous atrocities. The arrival of Islamic State should have been no surprise. The modern world is eager to condemn the aberration of Islamic State violence. Our judgements are based on the desire to find solutions, to prevent such phenomena, which are judged to be ‘irrational’. But the solution lies either in the minds of those who perpetrate such attacks, or in their defeat and destruction. Jihadists are a reaction to the success of modernism and they seek to exploit the tools of modernity to propagate a perverse, murderous and atavistically un-modern world view. They seek to construct a new form of power, but only through the negating excess of violence and death. In this, they have missed a fundamental truth about the construction and sustainment of states and repeated a folly of history, both premodern and modern. It was summed up by the historian Basil Liddell Hart, after the Armageddon of the First World War. He argued that the ends of war are not more war, but rather ‘the objective in war is a better state of peace’.