At best neutrality suggests passivity; at worst it implies moral indifference. As a result, histories of neutrality generally concentrate primarily on small, weaker countries, such as the Netherlands and Switzerland, and their inability to stand up to the demands of the belligerents during the First and Second World Wars. Frequently they did manage to make a tidy profit by selling to both sides, but that was at the cost of their national sovereignty: in the final analysis it was the countries waging war that decided whether they could remain neutral. If their neutrality was no longer considered important, then it quickly came to an end. This dispiriting image, based on a particular reading of twentieth-century neutrality, argues the New Zealand historian Maartje Abbenhuis, clouds our view of neutrality in the nineteenth century. Abbenhuis, by contrast, argues that we can only really understand the international relations of the ‘long’ nineteenth century – which lasted from the Congress of Vienna to the First World War – when we considered the vital role neutrality played in these relations. This is the point she tries, and largely succeeds, to make in her latest book, whose telling subtitle (‘Great Power Politics’) highlights that neutrality cannot be understood simply as the default policy of the small and weak.

Although neutrality has a long history, it was only during the nineteenth century that it developed into a highly useful diplomatic tool for both smaller and larger countries. This new neutrality was designed to delineate, as clearly as possible, the rights and responsibilities of those who waged war and those who did not, in order to reduce the risk of third parties being dragged into a conflict. This was supposed to reduce wars in both scale and scope, and thereby limit the risk that a conflict between European Great Powers would escalate to a war of ‘revolutionary’ proportions – the spectre of the French Revolutionary and Napoleonic wars that continued to haunt European statesmen – was limited. As part of the ever-expanding legal toolbox of neutrality, towns, rivers and even whole countries (Belgium, Switzerland) were made neutral by international agreement to further limit the prospect of a general European war; sources of potential conflict were thus identified and kept out of reach of all potential aggressors. Such rules and regulations were codified in international agreements in which legal experts and diplomats formulated precise rules to establish non-belligerents’ room for manoeuvre in case of conflict, and the rules of conduct for dealing with neutral territories. Naturally conflicts arose over neutrals’ rights and regulations, but, on the whole, the shared interest in European stability ensured compliance.

Moreover, during the second half of the nineteenth century, the efforts to solidify and expand neutral rights were led by an unexpected champion, argues Abbenhuis, global superpower Great Britain. Increasingly the British identified their interests as being imperial and economic in nature: it therefore became a prime British concern to defend the seaborne connections between its overseas territories and the metropolis, and between the Empire as a whole and its key trading partners; disruptions, even in wartime, might spell the end of the era of British dominance. Britain therefore relied on the global transport and communication systems continuing to functioning in wartime, whether London was an active belligerent or not. The cheapest and most effective way to do this was to safeguard this system by creating internationally accepted sets of rules and expectations that set limits to warfare.

Neutrality had two other important roles in the nineteenth century, states Abbenhuis. The notion of limiting, or even preventing war through the establishment of rules and regulations attracted a great number of ‘practical idealists’. The Red Cross for example, allowed ‘neutral’ ambulances to take care of the wounded from both warring parties. Neutrality also created, particularly in those countries who opted or were forced into longer-term neutrality, important building blocks for the construction of national identities. Sweden, the Netherlands and Switzerland all began to incorporate elements of neutrality in their collective self-identification.

Neutrality and the notion that all wars should be ‘limited wars’ go together, according to Abbenhuis, and therefore it is not surprising that in a ‘total war’ there was far less room for neutrality. Abbenhuis emphasises that the outbreak of the First World War in 1914 must not be seen as the ‘failure’ of neutrality – neutrality was a political tool to achieve certain goals, just as making war was and continued to be. However, neutrality did lose its systemic attraction during 1914–1918 because the belligerents ceased to attach any importance to the stability or the maintenance of the existing state system. Their explicit war aims were the creation of a new world order in which the political-cultural values of The Enemy would no longer have a place. Moreover, after the Great War of 1914–1918 (and even more so after the Second Great War of 1939–1945) the ‘neutral’ role of the stabiliser of the international system was taken over by new concepts such as collective security.

Not all of Abbenhuis’ ideas are as new as she makes them out to be. Her arguments rely fairly heavily on the notion that during the nineteenth century the European states had a common interest in the stability of the political system – a thesis first advanced in Paul Schroeder’s The Transformation of European Politics (1994) – and in the security of the rapidly developing world-wide transport and communications system – recently explicated in Mark Mazower’s Governing the World (2012). Moreover it meshes seamlessly with recent research into the history of international law, which unmistakeably flourished in the nineteenth century (see for example Stephen C. Neff, Justice Among Nations: A History of International Law (2014)). Her contribution to this literature is that she gives real substance to those ideas, using the history of nineteenth-century neutrality as a case study. The importance attached to stability and economic development is only tangible when it is put to the test, and that is certainly the case with neutrality during the many ‘limited wars’ and diplomatic crises of the ‘long’ nineteenth century. By illustrating how neutrality was tested but its underlying concepts never seriously contested, Abbenhuis greatly enhances our understanding of its importance to the nineteenth-century state system.

It is therefore unfortunate that in practice Abbenhuis’ analysis of the role played by neutrality in ‘great power politics’ deals chiefly with Great Britain. Great Britain indeed often remained neutral during the conflicts of the long nineteenth century, and Abbenhuis rightly maintains that it therefore had a certain interest in (the development of) neutrality law – even if it was waging war itself. Because of this, the role played by neutrality in the considerations in Paris and Berlin is given less attention and is primarily depicted by concrete outcomes – the fact that Germany respected the neutrality of Luxembourg during the Franco-Prussian War – while in the context of her argument the considerations that lay at the base of this, most particularly where they concern the link between neutrality and stability, would have been especially relevant.

Secondly it remains unclear why the ‘great powers’ abandoned neutrality, apparently very suddenly, in 1914. Naturally in the context of a war with a ‘totalizing logic’ (John Horne) there was little room for a concept that seemed so closely connected with the cause of maintaining stability. But the First World War did not immediately become a ‘total’ war in August 1914, nor was its revolutionary character immediately or even universally recognised and acknowledged until 1915. Nevertheless neutrality would be consigned to the scrap heap remarkably quickly after July 1914 – Germany invaded Belgium in early August 1914, and less than a month later Great Britain ignored all agreements concerning neutral trading rights.

However, these flaws do little to impair the quality of Abbenhuis’s ambitious and, above all, very readable book. It is essential reading for all those interested in the international relations in the nineteenth century.