In 1962 I published Power and International Relations, a book in which I undertook to analyse, criticize, and compare balance of power, collective security, and world government, treating these as the three leading theoretical approaches to the management of power in the global arena. Each of these approaches had its band of adulators and advocates who doubtless found my efforts at critical appraisal offensive. For a young American scholar of that era the adoption of an irreverent attitude toward balance of power was particularly problematic, because that approach figured prominently in the prevailing orthodoxy of Political Realism. It would have been safer to assume, rather than to examine, the merits of balance of power. I gave balance of power, like its two competitors, a mixed review.

In 1919 when the first tentative steps were taken to establish the study of international relations as an independent discipline, liberals in the United States and Europe believed that the First World War had been caused by European statesmen who had been pursuing policies designed to promote a balance of power. It was gloomily predicted, moreover, that the continuing influence of balance of power thinking would precipitate another world war. One of the major objectives of the nascent discipline was to identify alternative ways of organizing international relations so that the pernicious influence of the balance of power could be permanently eliminated.

Approximate parity in power capabilities between states creates uncertainty of victory if war were to occur. Whether, therefore, decisional uncertainty inhibits war between states or makes a breaking of the peace likely, is a central question in the host of ‘balance of power’ theories of interstate conflict. Some argue one way; others a different way; and some appear to argue one way, then the other. For along time each found support in armchair reflection—common sense bolstered with diplomatic anecdotes from ancient and modern state systems. Arguments could be made to command diverse historical examples because they rested upon the common assumption that calculations of power, security and conflicts of interest are essentially the same in any system of sovereign states. Anarchy, if you will, orders anachronisms. Now, however, each side can find support in quantitative evidence from far more systematic empirical analyses. The latter analyses are intended to bring some order and discipline to contrary insights by replacing anecdote with data.

Although, as the quotations above indicate, the question of the importance of the ‘balancer’ in balance of power systems has generated strong opinions from both critics and proponents, it has never stimulated a specific study of the balancer. The picture of the balancer as it currently exists has to be obtained by abstracting descriptions of the balancer role from general writings on the balance of power. This is unfortunate for even those authors like Padelford and Lincoln who saw the balancer role as critical, failed to devote more then a few paragraphs to the topic. The aim of this paper therefore is to try to clarify the nature and function of the balancer by synthesizing the views of analysts of the role over the past three centuries to produce a paradigm of the balancer strategy.

Students of international politics do not need to be told of the unsatisfactory state of balance of power theory. The problems are well known: the ambiguous nature of the concept and the numerous ways it has been defined, the various distinct and partly contradictory meanings given to it in practice and the divergent purposes it serves (description, analysis, prescription, and propaganda); and the apparent failure of attempts clearly to define balance of power as a system and specify its operating rules. Not surprisingly, some scholars have become sceptical about the balance of power ‘system’ and a few have even denied that balance of power politics prevailed in the nineteenth century. None of the methods generally used seems to promise much help. These have included studying the views and theories of balance of power held by individual publicists, theorists, and statesmen, making case studies of the balance of power in certain limited periods, analysing events and policies within an assumed balance of power framework, or constructing theoretical analyses comparing the supposed system of balance of power to other systems. Undoubtedly a method for operationalizing the study of the balance of power would be very valuable, and efforts to do this have yielded useful information. But the obstacles to establishing reliable indices of power and status and the problems of quantifying alignments and co-operation-conflict ratios in international affairs are formidable indeed.

Martin Wight once asked why the balance of power ‘has inspired no great political writer to analysis and reflection’?

Looking back in 1923, Winston Churchill wrote:

One rises from the study of the causes of the Great War with a prevailing sense of the defective control of individuals upon world fortunes. It has been well said, ‘there is always more error than design in human affairs’. The limited minds even of the ablest men, their disputed authority, the climate of opinion in which they dwell, their transient and partial contributions to the mighty problem, that problem itself so far beyond their compass, so vast in scale and detail, so changing in its aspect—all this must surely be considered before the complete condemnation of the vanquished or the complete acquittal of the victors can be pronounced.

Hegemonic stability theory, which argues that international economic openness and stability is most likely when there is a single dominant state, is the most prominent approach among American political scientists for explaining patterns of economic relations among the advanced capitalist countries since 1945. It has provided a research programme for scholars, both as a positive guide and as a foil against which to test alternative theoretical explanations.

The advent of nuclear weapons is clearly the single most important development which post-war balance of power thinking has had to accommodate. Although there have been earlier attempts to explore this relationship,1 an examination of the current debate on deterrence should throw some light on the issue of the continuing relevance of the balance of power concept.

The controversies surrounding the balance of power are both ancient and enduring, as the articles in this issue make clear. This brief concluding note highlights some of the convergences and differences in their approaches to these controversies. The choice of themes for this analysis is personal and selective, but it does reflect the central issues of balance of power theory and practice.