The near-simultaneous appearance of Volumes III and IV of Michael Mann’s The Sources of Social Power concludes a truly grand project of historical sociology. Along with the work of Anthony Giddens, W. G. Runciman, Ernest Gellner and Eric Hobsbawm, Mann’s project was one of the distinctive products of the intellectual conjuncture of 1970s Britain. A colleague of Gellner’s at the lse, Mann was, like Giddens and Runciman, in search of a constructive exit from the impasse of post-Marxian, post-Weberian sociology. But his original formation was that of a quintessential ‘history boy’—a product of the legendary Manchester Grammar School–Oxford pipeline. In the course of an itinerary that took him from social work to engaged labour research, the original idea for Sources of Social Power took shape in the mid-1970s. Conceived as a short book, it grew into a massive undertaking. The publication of Volume I in 1986 made Mann famous, and helped to revivify the field of historical sociology. Whilst contemporaries such as Giddens succumbed to the flesh pots of New Labour, Mann, ensconced in California, toiled on. The thousand-page Volume II, covering the period 1760–1914, appeared in 1993. Twenty years on, Mann presents us with a no less enormous, two-volume treatment of the twentieth century. It is a culmination that has been prepared by three other substantial books, on The Dark Side of Democracy, Fascism and Mann’s reckoning with the derailment of us policy after 9.11, Incoherent Empire.

The title of Mann’s project is programmatic. This is not a study of society or culture; it is a study of social power. The shift from society to power has both a constructive and a critical intent. Along with a number of other thinkers in the 1970s and 1980s, Mann set out to build an account of modern power that did not rely on an overly reified notion of ‘society’. Of course, social units may be made; but this is something to be explained, not assumed. Societies can be unmade as well, as Thatcher attempted to demonstrate. Mann therefore proposed the study of networks of power, as a more basic unit of analysis. There is a temptation in such a move to posit a new monism in the form of a single source of power. Instead, Mann launched an acronym—iemp. It doesn’t exactly trip off the tongue, and that is part of the point. It was a conglomerate, not a single term: Ideology, Economics, Military force and Political organization, all four governed by their own logics, are the constituent ingredients of power, defined as ‘the capacity to get others to do the things they would not otherwise do’, in order ‘to achieve our goals’. It is their combination and overlapping interaction that constitutes the networks and other crystallizations out of which states are formed.

Within this framework, Volume I expanded a multi-faceted narrative sweeping across millennia and culminating in an account of the rise of the West that avoided many, if not all, of the pitfalls of that venerable genre. It was received with great applause. More puzzling is the comparative silence that fell over Volume II, which works in a more painstaking fashion to explain the crystallization of Western power in the course of the nineteenth century, in the form of the European nation-state. It may seem paradoxical that someone who set out to refound sociology on a study of networks rather than societies should end up so resolutely focused on the nation. But for Mann, if the nation–state–society triangle did indeed come to dominate modernity, this is something for critical theory to explain, not to be taken for granted as its starting point. The 1980s and early 1990s saw a high tide for the constructivist analysis of the nation; Mann’s distinctive contribution was his focus on power. He speaks of nations not as imagined communities or invented traditions but as cages, the four corner posts of which are iemp.

The pay-off from this increasingly narrow, but increasingly deep, historical exploration comes at the juncture between Volumes II and III—Mann’s account of the outbreak of World War I. It may be to impute to Mann the particular preoccupations of post-imperial Britain, but it seems not implausible to see the brilliant final pages of Volume II as the point to which the entire previous undertaking has pointed: it is in looking back from the mind-boggling derailment of July 1914 that the arch of his construction becomes visible. If Volume I charted the rise of the West out of the pre-Christian era, and Volume II showed the way in which the nation-state emerged as the great rallying point for the energies of collective social power, then 1914 was Armageddon, the pivotal moment, the beginning of the end. As Mann himself put it on the penultimate page of Volume II, almost with a sense of relief: ‘The Great War exemplifies, horrifically, the structure of modern states and modern societies, as I have analysed them and theorized about them.’

What does he mean by this? In a sympathetic assessment of Volume I in these pages, Chris Wickham criticized Mann for saying in an off-hand remark that ‘minorities usually make history’. This, to Wickham’s mind, was both false as a general statement about history and reflective of a ‘traditional model of history as political action’. The quotation did not do justice to Mann; yet the irony of the modern era revealed so startlingly by the July crisis was precisely that, at the same time as social forces appeared to generate enormous momentum, elites came into play as never before. The culmination of this paradoxical process was the Cold War doctrine of Mutually Assured Destruction, when ill-matched pairs of men, wielding the destructive power of two continental states, held in their hands the future of life on our planet. That condition is the subject of Volume IV, but the extraordinarily labile quality of modernity was prefigured in 1914. What Mann’s account of power was able to show us about this moment is the fragile quality of what we mean by a state or a nation at such a moment of stress: the entire collectivity, with its immense destructive forces, can be pitched into conflict as the result of a disastrously counterproductive interaction between parliaments, military staffs, mass publics and economic interests. Though each was separately rational, the upshot was appalling. As Mann put it, the polymorphous power formations which he described states as being were ‘only reflecting modern society, equipped with massive collective powers, their distributive power networks entwining non-dialectically’. In the hands of one of his French counterparts, the suggestive idea of ‘non-dialectical entwining’ might have opened out into a deeper theorization. Mann himself prefers more straightforward language: the reality of modern power was ‘patterned mess’.

If crisis was the dramatic culmination of Volume II of the Sources of Social Power, in Volume III it becomes the dominating theme of the entire narrative. Over 500 pages, Mann offers his readers a fast-paced survey of the dramas of the early twentieth century, from the outbreak of World War I to the end of World War II, by way of the Russian and Chinese revolutions, fascism, Stalinism, Imperial Japan, the emergence of European social citizenship and the American New Deal. It is a narrative that is, as always with Mann, focused on the ‘leading edge of power’. But, as a history of the twentieth century must, it takes in a far wider sphere—virtually the entire Northern Hemisphere, stretching from the United States, Western Europe and the Soviet Union to China and Japan. It is a story, in Mann’s terms, of ‘polymorphous globalizations’, driven by the complex interactions of the three most basic power organizations of human societies—capitalism, empires and nation-states. He concedes that ‘by half-closing our eyes, it is possible to construct an onward-and-upward evolutionary story’ even out of the grisly raw material of the twentieth century. But, as Mann has always insisted, such law-like accounts of modernization are incapable of seizing the true drama of the development of modern power, which consists precisely in its heterogeneous, haphazard and often crisis-prone accumulation. Unlike its two predecessors, Volume III of the Sources of Social Power is therefore dominated by a series of complex events, what Mann calls the ‘Three Great Disruptions’—World War I, the Great Depression and World War II. This theme, he promises us, will continue in Volume IV, which centres on the Cold War arms race and the global environmental crisis. Mann is acutely conscious of this shift in the focus of his analysis. Looking back in the aftermath of 1914, he says, it cannot but seem to us that earlier eras were less prone to such savage disruptions; less contingent, more governed by broader patterns of social development. Is this true? Mann leaves the question open. Certainly the challenge for a twentieth-century history is to assess ‘to what extent contemporary power relations are the product of the logic of development of macrostructures, and to what extent these have been redirected by both timely conjunctures, producing world-historical events, and individuals in positions of great power.’

It is the extent of the rupture in 1914 that makes these questions inescapable. The problem of the ticklish transition between the nineteenth century and the twentieth-century ‘age of extremes’ is not one that Mann faces alone. Two recent grand-narrative accounts of global modernity, Christopher Bayly’s Birth of the Modern World (2004) and Jürgen Osterhammel’s Die Verwandlung der Welt (2011) stop abruptly and frustratingly short in 1914. On the other side of the great divide, Mark Mazower’s account of the twentieth century, Dark Continent (2000), managed the remarkable feat of boot-strapping its way into the interwar period without a serious discussion of either World War I or the Russian Revolution. Amongst those who do bridge the divide, Arno Mayer’s Why Did the Heavens Not Darken? (1988) did so by extending the nineteenth century deep into the twentieth, thereby making even World War II and the Judeocide into rearguard actions of the Ancien Régime. More compellingly, Charles Bright and Michael Geyer, whose work Mann unfortunately disregards, have proposed in a series of articles that we should think in terms of a long twentieth century, beginning not in 1914 but with the earth-shaking upheavals that came between the hungry 1840s and the Paris Commune.