Andre Maurois tells the story of how, as relations between Germany and Britain worsened in the years before the first world war, the German ambassador in London sent a dispatch to Berlin saying that the vast majority of Britons wanted peace, and so did the king, Edward VII. “Lies,” the Kaiser scribbled in the margin, “he wants war. But I have to start it, so that he does not have the odium.”

The contradiction between the desirability of peace and the seeming inevitability of war lies at the heart of 20th-century European history. In 1900, European states were both defined and legitimised by their monopoly of violence and particularly their capacity to wage war. By the end of it, their legitimacy rested on the successful avoidance of war, which in any case they no longer had the capacity to conduct in a whole-hearted manner.

This great shift, in politics, economics and psychology, is the subject of The Monopoly of Violence: Why Europeans Hate Going to War by the American scholar James Sheehan, a specialist in German history. The British sociologist Martin Shaw coined the phrase “post military” to describe the phenomenon of west European societies which have become essentially pacifist while maintaining small, if still sometimes quite lethal, professional armed forces. The conservative American writer Robert Kagan more recently seized on the change to propose an exaggerated theory of European-American difference. So it is an oft told tale, although there are many perplexing, as well as unfinished, aspects to it.

Sheehan’s version has much of interest. One of his arguments is that, as the century began, pacifism and militarism had a common ground in their concern for solidarity and community in societies disturbed and traumatised by economic change and the growing reach of more powerful central governments. He notes that both Max Weber and Emile Durkheim, the two great social thinkers of the era, saw war as “reviving the sense of community”. He quotes Spenser Wilkinson, once the Manchester Guardian’s military correspondent, lamenting that “we have forgotten nationhood and have become a conglomerate of classes, parties, factions, and sects.” Pacifism, by contrast, saw in the cultivation of the sense of brotherhood across boundaries and the growth of what we would call transnational institutions, the antidote to the same loss of community which worried the militarists.

Such views were both therapeutic in intention, and, in their different ways, romantic. The dismal realities of war in Europe, with its transfer to the continent of the colonial ruthlessness which had scarred the non-western world, made more terrible by the application of advanced industrial techniques, undermined both militarists and pacifists. Of course the US continues to use force outside those boundaries more readily than Europe, yet it does so in face of the same tendencies that shape other settled societies. Almost all are dubious about the utility of force, understand the severe limits of what can be asked even of professional militaries, and have lost the idea that war is a means of building community. Yet they also know well that force can hardly be entirely discarded in a world where small minorities pose large dangers, and where the breakdown of weak societies can set off chronic internal conflicts. - The Guardian