For ten months from the summer of 1925, a forty-three-year-old political scientist named Sarah Wambaugh found herself living aboard a transport ship moored off the west coast of South America. This was not something the American scholar did regularly. It was, however, a direct result of her success – for she had been asked by the Peruvian government to help them prepare for an upcoming vote which they hoped would see a remote region occupied by Chile return to the Peruvian sovereignty from which it had been seized generations earlier. Already the world’s leading specialist on the international plebiscite, Wambaugh had visited the sites of all the recent plebiscites held in post-war Europe but had not yet experienced one herself. It was here in the region known as Tacna-Arica that she would finally come face to face with what self-determination has all too often meant in practice: conflict and brutality. Forced by the Chilean campaign of violence to live aboard the ship which transported them, Wambaugh and the Peruvian delegation persevered as best they could, but in the end the plebiscite was abandoned. Bitter as this experience was, for Wambaugh it only served to fire her with conviction, making clear to her what she already believed theoretically: the practical implementation of self-determination via the ballot required powerful safeguards and an impartial international presence in order to be fair.

For Wambaugh personally, this would be the first of a number of adventures in some of the world’s political hot spots. Her career at the intersection of the two great pillars of the incomplete world order propounded by Woodrow Wilson – self-determination and international organisation – would see her advise the League of Nations on the long-planned 1935 plebiscite which saw the industrial region of the Saar vote to re-join a Germany now run by the Nazis. Just over a decade later she would step into civil war–torn Greece, advising the first major international election monitoring exercise, while a few years later she was packing her bags to join the United Nations in Kashmir, before the planned plebiscite was cancelled. In between, Wambaugh would define the normative principles for the international plebiscite in a series of works which had an important, if unpredictable, influence in their own day, and continue to shape how self-determination by the ballot is thought about today. Well known in her own day among liberal internationalist circles, at certain periods of time – particularly during and after the Saar plebiscite – Wambaugh achieved worldwide attention.

By the turn of the twenty-first century, however, Sarah Wambaugh was a forgotten figure. While her major works on plebiscites were still cited, the few discussions of their author were brief or incomplete.Footnote ¹ The most prominent discussion of Wambaugh’s work at this time is contained in Karen Knop’s 2002 Diversity and Self-Determination in International Law, whose enlightening analysis is tantalisingly brief.Footnote ² The all too common erasure of women from the historical record was compounded in Wambaugh’s case by her own career. The plebiscite, once seen as a promising democratic solution to international conflict, seemed now, amidst the breathless post–Cold War vision of a peaceful and borderless world, to be a vestige of a disruptive past. A quarter of the way through the twenty-first century and the world looks very different. Borders are again redrawn by force and sham elections held to legitimate them; democracy everywhere seems strained and stumbling. Yet simultaneously, women’s roles in international politics and history have come to be recognised as never before.Footnote ³ Sarah Wambaugh and the plebiscite now seem pressingly relevant.

As a consequence, Wambaugh has finally begun to receive much needed attention from scholars. Dagmar Wernitznig’s 2022 article examined Wambaugh’s analysis of, and involvement in, several particular plebiscites through the lens of gender.Footnote ⁴ A year later, a brief contribution by Imogen Saunders in a series of Portraits of Women in International Law further sketched out Wambaugh’s career and importance in that field.Footnote ⁵ Meanwhile a passage from Wambaugh’s first book on plebiscites is rightly included as part of the contributions to Women’s International Thought: Towards a New Canon, published in 2022.Footnote ⁶ Building upon previous scholarship often primarily focusing on women’s fight for suffrage,Footnote ⁷ this burgeoning field has pointed to the individuals, organisations, and networks involved in a broader global struggle for women’s rights and representation in international affairs. Sarah Wambaugh’s career is particularly revealing in this light, both in terms of what she had in common with other women’s experiences and the ways that she was exceptional.

Immersed in the fight for women’s suffrage in the United States, Wambaugh’s subsequent career in international plebiscites was itself a demonstration of the global scale and interconnections of that struggle.Footnote ⁸ Her consolidation of the principle of female suffrage within her normative prescriptions for the plebiscite – at a time when this was far from universal – was perhaps her most enduring direct contribution in that regard.Footnote ⁹ Yet Wambaugh was also, it might even be said primarily, interested in another key plank advocated by women’s peace activists – international organisation. One of the few women to occupy substantive roles within the League of Nations, albeit briefly, Wambaugh’s expertise managing politically sensitive elections set her apart from women like Dame Rachel Crowdy, Head of the League secretariat’s Social Section, whose careers were usually limited to the ‘soft’ elements of international affairs.Footnote ¹⁰ Wambaugh, by contrast, was involved in ‘hard’ political and security dimensions – the international plebiscite being inherently political in nature. Her scholarship on how these votes were to be undertaken, meanwhile, was read and taken seriously by male policymakers.

If Wambaugh’s experiences seem unusual for women of that era, and decades beyond, who were largely marginalised from the male-dominated fields of academia and diplomacy, it was because they were. Unlike journalist and historian of Europe’s interwar international affairs Elizabeth Wiskemann, whose initial academic career was scuppered by male jealousy,Footnote ¹¹ or feminist sociologist Ann Oakley, whose groundbreaking books on gender were disdained and unread by her prominent social scientist father,Footnote ¹² Wambaugh had supportive male mentors, including her own law professor father. Yet in other ways Wambaugh’s career encountered setbacks all too familiar to women. Important as they were, outside of her involvement in several international hotspots, Wambaugh struggled to attain meaningful employment in the international field. Her attempts to become a diplomat for her country were rebuffed; her wartime desire to help with official post-war planning unfulfilled.Footnote ¹³ While she enjoyed a secure research role with her alma mater, the then-all-women Radcliffe College, her academic position was far from prestigious, although this was perhaps at her own request. She was no Virginia Gildersleeve, college dean; nor like Wiskemann did she late in life become a professor.Footnote ¹⁴

This paradox – a successful pathbreaking woman in international relations on the one hand, and a marginalised and ignored figure on the other – was a result of Wambaugh’s identity and reputation as a technical expert in a narrow field. As one wry journalist noted in a profile published late in Wambaugh’s career, if you wanted ‘a life work involving agreeable working hours, little competition and a good deal of distinction, you might take up plebiscites’.Footnote ¹⁵ Wambaugh was effectively the only expert in her field, and as the quotation suggests, this had benefits and drawbacks. Distinction she certainly gained from her expertise on the international plebiscite, but her close association with it proved a liability when the technique fell out of favour. In the public eye, meanwhile, her expertise in plebiscites tended to overshadow the other topics she wrote about and advocated for – including the League of Nations, collective security, and an international armed force. Having few competitors was not itself enough to propel Wambaugh’s career past the prejudices of the age. It helped, certainly, that she was a woman of European descent from an established middle-class academic family, but the nature of her expertise mattered too. Wambaugh’s scholarship on the international plebiscite, still essential reading for understanding its early history, was not a philosophical, or even purely historical, study of the plebiscite.Footnote ¹⁶

Rather, her factual approach was explicitly aimed for practitioners – the titles of all of Wambaugh’s major books are suffixed by the proviso that they come ‘with a collection of official documents’. As a result, Wambaugh became an expert on the technical aspects of how to ensure a free and fair vote, while eschewing the major political questions over when, where, and why such votes should occur in the first place. This split between politics and the technical – problematic in its own way – enabled Wambaugh’s career. Her ostensibly apolitical role as technician of the plebiscite apparatus granted her access to male spaces of political power without seemingly encroaching on them. Tracing the development of the technical provisions Wambaugh came to write for the plebiscite, and the way she imbedded particular internationalist forms into them is consequently an important component of this book. But it is not the only one. As Ann Oakley has written of her own works, ‘[w]hat happens to texts and ideas and conceptual devices once they’re placed in the public domain is beyond the deviser’s control’.Footnote ¹⁷ Much the same could be said about Wambaugh’s ideas on the plebiscite. At times influential, at other points consciously ignored, their impact was far from straightforward and often rife with unintended consequences. To fully grasp the significance of Wambaugh’s thought on the plebiscite, and career as a whole, therefore requires that they be studied alongside the plebiscite’s role in international politics.

The word ‘career’ is used advisedly. As noted by the few scholars who have examined Wambaugh’s papers,Footnote ¹⁸ contained in several separate collections in Harvard University,Footnote ¹⁹ there is virtually no material of a personal nature found within. While this volume has drawn on a wide range of additional sources, including Wambaugh’s correspondence found in the papers of other internationalists and women’s rights pioneers, the picture that emerges remains focused on her professional work and interests. This was not necessarily an accident, with Wambaugh herself acutely aware of the dilemmas facing unmarried professional women.Footnote ²⁰ When asked in a 1928 alumni survey whether a woman could ‘successfully carry on a career and marriage simultaneously’, she replied that ‘[i]t depends on the career & the woman’.Footnote ²¹ A decade later, when a journalist had the temerity to ask why she never married, Wambaugh is said to have replied coolly that her ‘interest is in nations, not individuals’.Footnote ²² This book is consequently a critical intellectual biography of Sarah Wambaugh as well as an international history of the plebiscite. Given how intertwined the two are, it would in fact be impossible to tell one story without the other – and it is a story which needs telling.

As Jörg Fisch notes in his history of the right of self-determination, ‘no comprehensive history of the plebiscite or the referendum has been written’.Footnote ²³ This volume will go some way to rectifying this, albeit with caveats. As with Wambaugh’s own research, this book examines the plebiscite as a tool of international, not domestic, relations. Additionally, no distinction is made here between the words ‘plebiscite’ and ‘referendum’; however, the former was the dominant term, used almost exclusively in Wambaugh’s own day, and as such also here. Indeed, the plebiscite’s fall from grace was itself part of the reason the term ‘referendum’ came to replace it. On a related terminological note, place names are given in the forms most commonly used in English at the time which, especially for the plebiscites held in Central and Eastern Europe, were frequently derived from the German. What, then, does a study of Sarah Wambaugh and the plebiscite reveal?

For one, the trajectory of her thought is itself illuminating. Although her major works eschewed the overtly political dimensions inherent in the plebiscite, viewed from a wider lens, it is possible to trace a transformation in Wambaugh’s thought about how the plebiscite ought to be used. Like many others when it came to self-determination, Wambaugh’s position changed from a youthful optimism (or naivety) to one of caution, and during the Second World War briefly outright rejection, settling finally on the plebiscite as a tool of last resort. In this she presaged what more recent international legal scholars have come to conclude – namely that the aim of prudent policy lies in Escaping the Self-Determination Trap, as Marc Weller’s eponymous study is titled.Footnote ²⁴ Along with Allen Buchanan, Hurst Hannum, Margaret Moor, and other scholars of law and ethics, she saw self-determination in the form of secession as legitimately granted only remedially and in response to extreme violations of human rights,Footnote ²⁵ the preferred response being autonomy and complex power-sharing instead.Footnote ²⁶

While self-determination is of primary interest to most international legal scholars following the birth of the United Nations, whence the principle became a positive right in international law,Footnote ²⁷ historians have seen the efforts to contain it as beginning earlier. This process was memorably described by James Mayall as ‘the domestication of national self-determination’, a phenomenon which began ‘almost as soon as national self-determination was advanced as the new principle of international legitimacy after 1918’.Footnote ²⁸ The idea that the principle has been ‘domesticated’ is also at the heart, and part of the title, of Jörg Fisch’s comprehensive history, which declares that ‘the history of the right of self-determination is the history of its restrictions’.Footnote ²⁹ One way this domestication took place was through the implementation of alternative solutions, such as international territorial administration and minority protection, but also the wholesale transference of populations. These techniques were also the outcome of the longer-term shift towards what Eric Weitz has termed ‘population politics’.Footnote ³⁰ Wambaugh and the plebiscite were connected to these developments, and cast new light upon them.

Already in the early 1920s Wambaugh came to see the League of Nations–run international administration of the Saar and Upper Silesia as alternatives to the stark choices on offer from self-determination in disputed areas.Footnote ³¹ Meanwhile, if she was hardly connected to the League’s system of colonial mandates,Footnote ³² and only tangentially involved in its intricate minority protection system, intensely disliked by the Eastern European states to which it was exclusively applied,Footnote ³³ Wambaugh was certainly well acquainted with the milieu of internationalist scholars and League officials who established them. More revealing was her changing position in regard to the alternative to protecting minorities or letting them decide their sovereignty – expelling them. Compulsory population transfer, as it was politely known, had been written into the post–First World War settlement at precisely the moment when the post-war plebiscites were revealed to be chaotic and inadequate.Footnote ³⁴ If Wambaugh initially focused on improving the plebiscite, later in life – as her enthusiasm for self-determination waned – she would explicitly endorse population transfer as a tool for peace. One of the major reasons for this endorsement was that population transfer had been tied to, and given legitimacy by, the League of Nations.Footnote ³⁵

To say Sarah Wambaugh was enthusiastic about the League would be an understatement. Even at the start of her career examining plebiscites Wambaugh found the League – and advocacy for American entrance into it – to be a more compelling preoccupation. Unsurprisingly the detailed normative prescriptions she prepared for the plebiscite saw her imbed the League into the running of the vote in all but name. Key to these prescriptions was the idea of ‘neutralisation’ – by which Wambaugh meant holding the plebiscite under impartial international auspices. If these same characteristics underpin her praise for the League, it was also precisely during this time that the very concept of neutrality was in flux.Footnote ³⁶ From the broader historical perspective, then, Wambaugh’s greatest contribution to the ‘domestication’ of self-determination – a revealing turn of phrase in light of her gender – was the manner in which she provided for its neutralisation – or, we might say, its ‘neutering’.Footnote ³⁷

This is no mere etymological flight of fancy. As Wernitznig notes, Wambaugh’s studies of the plebiscite were attuned to women’s experiences, even when they were not allowed to vote, as in Tacna-Arica.Footnote ³⁸ While the inclusion of women’s suffrage was the most explicit feminist item in them, the technical provisions through which Wambaugh aimed to neutralise the plebiscite were created to prevent the kind of violent repression she witnessed there from occurring in subsequent plebiscites. ‘Better any form of paternalistic determination, however undemocratic’, she would conclude in her 1933 Plebiscites since the World War, which set out her normative framework for the ideal plebiscite, ‘than a plebiscite lacking the measures necessary for the protection of both parties’.Footnote ³⁹ Neutralisation was thus the sine qua non for a genuine democratic plebiscite, and the opposite of ‘paternalism’ – another revealing turn of phrase. Yet inherent in this statement was that, failing these standards, it was better to have no democracy at all when it came to determining a region’s sovereignty. If not for exactly the same reasons, this statement would indeed foreshadow the reduced role which the plebiscite would ultimately come to occupy in international affairs.

The examination of the plebiscite through the lens of gender seems natural given the overlap between the domestic struggle for women’s suffrage and women’s increased involvement in world affairs after the First World War. Yet historians have only recently begun to pursue this angle, with Wernitznig’s brief study complemented by a chapter by Tina Bahovec in an edited volume on the Versailles era plebiscites published in 2024.Footnote ⁴⁰ Historical studies on individual interwar plebiscites likewise exist, although, as Jörg Fisch notes, there is no overarching historical study of the technique. Part of the reason is that the plebiscite has primarily been examined from juridical or political science perspectives. Scholarship on the nineteenth-century plebiscites is still dominated by Wambaugh, while her treatment of the interwar plebiscites remains essential reading. In the years after the Second World War there have been a handful of studies detailing the plebiscite in the decolonisation process,Footnote ⁴¹ but none as comprehensive as Wambaugh’s earlier contributions. Although Yves Beigbeder’s 1994 work on plebiscites, referenda, and domestic election monitoring discusses normative practice,Footnote ⁴² the post–Cold War treatment of the plebiscite is dominated by legal scholars and political scientists.Footnote ⁴³

One of these, Matt Qvortrup, is today the leading scholar of the technique. An advocate for direct democracy,Footnote ⁴⁴ Qvortrup is a kind of modern-day Wambaugh, having helped the United Nations organise the 2011 South Sudan independence referendum.Footnote ⁴⁵ His analysis and categorisation draw on some two hundred domestic and international plebiscites and is organised around the purpose to which the vote was held: whether its goal is secession, union with another country, and so forth, from which he attempts to establish a formula for determining conditions under which votes are successful.Footnote ⁴⁶ However fascinating such research might be, this book sides with Mark Mazower’s critique of certain international relations scholars as suffering from ‘[s]cience envy’ – something which leads them to downplay ‘the possibility of taking contests of ideas and philosophies seriously in world affairs’.Footnote ⁴⁷ It is from this perspective that the international plebiscite is studied here: not as an unchanging vessel providing a statistical dataset, but as a form of organisation whose role, nature, and impact changed over time. In this regard, when this book refers to the ‘technique’ of the plebiscite – a term Wambaugh herself frequently used – what is meant is more in line with what Ralph Wilde, in his inquiry into international territorial administration, terms a ‘policy institution’.Footnote ⁴⁸

Mazower’s critique of ‘science envy’ is particularly apposite because it was something Sarah Wambaugh could be said to have suffered from too. An inheritor of the enthusiasms of the American Progressive movement, and the widespread belief that science could improve all facets of life, like many others, Wambaugh believed it possible to conduct international politics in an impartial and neutral manner. It was this belief which underpinned her commitment to the League and also her plans for the plebiscite. Indeed, her idealised plebiscite came to resemble a science experiment on a large scale – with sealed borders and neutralised administration, the aim was to reveal the true popular will and present it, as she explained in her first book, ‘in a definite statistical fashion’.Footnote ⁴⁹ Sitting at the heart of the technical apparatus designed to achieve this, however, was something less than scientific – public opinion.Footnote ⁵⁰ As Glenda Sluga reminds, the rise of psychology had implications on understandings and perceptions of the nation,Footnote ⁵¹ and this psychological turn impacted Wambaugh’s thought too. Wambaugh well understood that in order for voters to actually cast their ballots as their hearts and minds intended, they had to have full confidence that they could do so – and not fear reprisals, or worse, as a result. Perceptions of the plebiscite’s impartiality therefore mattered as much as the reality. It was not enough merely to perfect the technical aspects of the plebiscite; rather, the publicity surrounding the nature of the vote itself had to be actively attended to. This tension between the demands of impartial science, on the one hand, and Wambaugh’s skills in public relations, on the other would play out across Wambaugh’s career, and is one of the threads of this book.

The dilemmas inherent in this came to a head during the Saar plebiscite of 1935, an operation in many ways the defining crux of Wambaugh’s career, and certainly of this book. Wambaugh played a central role in planning and directing the operation, yet it was not only in regard to the plebiscite’s technical dimensions but also in regard to its publicity where she played the decisive role. Here Wambaugh’s cumulative experience in the women’s suffrage and peace campaigns, her advocacy work for the League, as well as the attention she paid to public opinion and propaganda during the Tacna-Arica plebiscite and in her studies of the technique, all proved a tremendous asset. While there were good reasons to fear that the vote would be far from free and fair, with Nazi pressure looming across the border, the plebiscite would come to be nearly universally lauded as a triumph of technical precision, which not only guaranteed a fair vote but also seemed to herald a new age of the peaceful settlement of international disputes. As a consequence, Wambaugh herself became one of the major stories of the plebiscite, and was recognised for her achievements.

In this, Wambaugh was again exceptional. As Naomi Oreskes suggests in her examination of why women have been rendered invisible in the history of science, ‘heroism, rather than objectivity, was a central defining virtue’ of scientists in the early years of the twentieth century.Footnote ⁵² A key part of this was the mystique of the lone scientist struggling against ignorance, making discoveries in the dead of night. Against this masculine heroic vision, women’s scientific contributions, frequently as calculators and quantifiers of experimental data, done as part of larger teams of researchers, could be overshadowed and erased.Footnote ⁵³ As far as political science went in the Saar, however, things were different. Wambaugh was the hero. The sole expert in her field, operating in a tense and dangerous political environment, Wambaugh fit neatly into the heroic myth. As a consequence, the myth overrode resistance to her gender. Indeed, amidst the worldwide media attention of the Saar plebiscite, Wambaugh became a source of inspiration for both feminists and the general public. Yet if the heroic vision played a part, it was Wambaugh’s objectivity which was equally remarked upon. But was it justified?

The tendency towards exaggeration, exhortation, and simplification, so necessary for success in the shaping of public opinion, was not always conducive to detached scholarship. For Wambaugh the dilemma was strongest when it came to the League of Nations, where even her scholarly discussions could merge into propaganda. As she came to implicitly write the League into the rules for her ideal plebiscite, the possibility grew that her sympathy towards the former would bleed into the latter. When the plebiscite itself moved from the object of study to the subject of Wambaugh’s activities in the Saar, meanwhile, her objectivity became even more compromised. One result is that, unlike her earlier books on the plebiscite – which examined operations conducted in the nineteenth century as well as the post-war votes in which the League was all but absent – her final major work on The Saar Plebiscite is the least intellectually satisfying. Observing that plebiscite as a journalist meanwhile, Elizabeth Wiskemann, in one of the few dissenting critiques issued amidst the near-uniform praise, would reach conclusions diametrically opposed to Wambaugh’s. Years later, Wambaugh too would come to admit privately that the plebiscite had been less than perfect.

Wambaugh had been blinded by her own vision of the League as harbinger of a neutral and impartial science capable of taming the unstable and irrational world of politics. Her uncompromising praise of the Saar plebiscite, meanwhile – intended to demonstrate the possibility of the attainment of that world – would unintentionally contribute to the reputational implosion of the plebiscite as a whole. With the plebiscite seen as a triumph, it was no surprise that many others, including men with power and influence, saw it as a model for emulation. As European tensions mounted, the Saar plebiscite appeared as one of the few solutions capable of bringing all sides together: a triumph for international cooperation, for political science – and for Nazi Germany. When these tensions culminated in 1938, the example of the Saar plebiscite was literally written into the Munich Pact that would ultimately see Czechoslovakia devoured by its fascist neighbour. Sarah Wambaugh was not to blame for that calamitous outcome, but as the world once more became engulfed in war, her idealism would be placed in stark relief and she would take some dreadful lessons to heart.

The first key lesson was the deprioritisation of self-determination at the international level, with the concomitant embrace of compulsory population transfer. The second lesson, related to, but partly contradicting the first, was the acceptance of American power as the necessary condition for an eventual democratic world order. Like many other disillusioned liberal internationalists of her generation, Wambaugh came to embrace American power wholeheartedly, seeing communism as the new fascism, and demonstrating a willingness to cooperate with this power, even at the expense of her own ideals. For Wambaugh personally, this resulted in the bitter experience of remaining silent about one of the major flaws she observed during her time with the first major multilateral election monitoring mission held in Greece in 1946 – that women were not allowed to vote at all. Unlike in Tacna-Arica, whose women were also denied suffrage, Wambaugh would not draw attention to this fact, remaining silent in public, and even praising the Greek elections in order to burnish the credentials of the anti-communist regime which emerged from them.

Intertwined with the story of Sarah Wambaugh’s long retreat from idealism is that of the development of the normative principles she wrote for the plebiscite, and the ways in which they interacted with, and impacted, international politics. One of the key observations is that Wambaugh’s painstaking academic research was successful in rehabilitating the reputation of the plebiscite after the chaotic experiences of those held after the First World War. Although this was compounded by good fortune and good marketing, of major importance was the way Wambaugh developed clear normative principles which crystallised into a concise set of eighteen points. Easy for policymakers to grasp, these eighteen points would reappear frequently whenever plebiscites were discussed. The impact of Wambaugh’s rules for the plebiscite was far from straightforward, however. As Paul Schroeder notes of the many Enlightenment-era schemes for improving international politics, the actual results of such well-intentioned plans are ‘indirect, indeterminate, unpredictable, and often ironical’ with outcomes depending ‘less on their intrinsic nature and purpose than on how they enter into the processes of decision-making and policy formation, how statesmen and publics react to them, and what influence they exert when filtered through the policy process and mixed in with the other ingredients of international politics’.Footnote ⁵⁴ Much the same can be said of the plebiscite.

These themes are explored across the book’s seven chapters in a largely chronological fashion. Chapter 1 begins with the plebiscite’s re-emergence in the first flush of Wilsonian optimism, of which Wambaugh was an enthusiastic acolyte. Largely neglected by the men planning the world order following the First World War, it was Wambaugh who provided the most detailed study then available about the plebiscite’s history and future use. Although her normative rules were protean, a key provision was the inclusion of suffrage for women as well as men, the domestic struggle for which Wambaugh was a part. The chapter ends by discussing the reasons behind the fragile triumph which saw universal suffrage written into (nearly) all the post-war plebiscites. Chapter 2 examines the sometimes chaotic reality of the plebiscites actually held in Europe, which resulted in the technique being discarded by the world’s leading statesmen. Wambaugh would visit these locations soon after the plebiscites were held, while her earlier brief tenure in the League secretariat gave her a first-hand view of what she saw as an entirely different way of managing international affairs.

Chapter 3 explores the foundations of Wambaugh’s political thought and worldview. Science, neutrality, and public opinion loom large as important aspects critical to understanding her ideas. Wambaugh’s faith in science was widely shared, and central to it was neutrality – the notion of the detached and impartial observer providing objective knowledge. Yet in international law, neutrality had different connotations, whose meanings were then in flux; the old neutrality of abstention from conflict seemingly voided by the League’s commitment to collective security. America’s failure to join the League threatened to scupper this, as it insisted on its old-style rights as a neutral, something Wambaugh and other pro-League internationalists condemned. Alongside this transformation, serious debates were taking place about the role which knowledge, education, and the public should play in democratic political affairs. The chapter places Wambaugh’s thought on the plebiscite into the context of contemporary debates by Walter Lippmann and John Dewey, as well as the radically different ideas of German legal philosopher Carl Schmitt. It also points to the ways that public opinion was itself vital to, and part of, the technical apparatus she devised for the plebiscite. The chapter ends with a study of Wambaugh’s own publicity campaign for American entry into the League during the years 1921–1925.

Wambaugh’s advocacy work was interrupted by the unexpected opportunity to join the Peruvian delegation as technical advisor during the violent and eventually abandoned Tacna-Arica plebiscite of 1925–1926. As explored in Chapter 4, her painstaking rehabilitation of the plebiscite technique began here, with that lengthy process seeing Wambaugh become the first woman to address the Academy of International Law in The Hague in 1927, her series of lectures there subsequently expanded into her major 1933 study Plebiscites since the World War. The normative conclusions she reached called for the complete ‘neutralisation’ of the plebiscite, which was to be imbedded within a large-scale international operation. As examined in Chapter 5, Wambaugh would play a leading role in putting these principles into practice in what was seen at the time as the ideal plebiscite – the high-profile 1935 vote in the industrial Saar territory, disputed between France and Germany, but administered by the League. Including a huge team of international officials and the first multinational military force under international control, the operation was lauded as both a technical triumph and a victory for international cooperation. This was in no small measure due to Wambaugh, who, in addition to her official role, conducted a successful press campaign to bolster confidence in the vote.

The Saar plebiscite saw Sarah Wambaugh reach the height of her fame, yet if the vote was a victory for international cooperation, it was a bitterly ironic one, with the political result being an overwhelming Nazi triumph, made all the more so because of the very precautions put in place to persuade the world of its fairness. Chapter 6 traces the consequences of this contradiction as it played itself out in the denouement of Europe’s interwar crisis in the Munich Pact of September 1938. Even though it was apparent that the plebiscite for the Sudetenland written into that agreement looked nothing like the long-planned and intricate Saar operation of three years earlier, the latter was explicitly endorsed as the model to be followed. When it came time to implement the agreement the contradiction could no longer be sustained, and the plebiscite was abandoned. This state of affairs continued throughout the war that erupted a year later, with the technique now scorned by liberal internationalists, including Wambaugh.

Despite her reappraisal matching the positions of the official wartime entities planning the post-war order, like other women, Wambaugh was excluded from these circles – with her association with both the plebiscite and the League marginalising her even further. This was not the end of her career, however, and as Chapter 7 explores, the post-war world suddenly appeared ripe for Wambaugh’s expertise once more. Yet this last chapter of her life, and this book, reveals a world where this expertise was turned on its head and her life’s work placed in stark relief. Wambaugh’s role in the 1946 election monitoring mission in Greece saw her knowledge of international plebiscites applied to the context of a controversial domestic election, but also saw her insights relegated to second place as the mission embraced the new field of scientific sampling. Wambaugh’s conclusions as to the nature of the election and its outcome were heavily influenced by her aversion to communism, the result being that she prioritised the defeat of that ideology over women’s suffrage itself. Meanwhile the weakening of European power and the era of decolonisation appeared to offer new avenues for the plebiscite.

Wambaugh’s time advising the ultimately abandoned United Nations plebiscite in Kashmir saw her expertise now questioned as being inapplicable to a non-European setting. This admirable cultural sensitivity had an undercurrent of prejudice however, as the first United Nations plebiscite actually held suggests. Held in 1956 in British Togoland, the vote was run by the British, with a small international presence merely monitoring the operation, thus eschewing most of the heavy controls which Wambaugh had previously called for. Less than a year earlier, meanwhile, in a referendum held once again in the Saar, the spectre of the previous vote loomed large, as did Wambaugh’s prescriptions. Asking voters whether they wished to become a ‘Europeanised’ territory, the commission holding the vote consciously modelled its operations on the 1935 plebiscite. Yet the same heavy controls intended to neutralise the voting region were now found by many to be unnecessary in the new post-war Europe. These plebiscites, which heralded the technique’s much reduced role in the process of both decolonisation and European integration, coincided with Wambaugh’s death in 1955.

This book thus tells the story of the rise and fall of a tool of international governance whose turbulent history once played a key role in world affairs, and whose foremost expert did too. It captures a moment in time when hopes for a more democratic world order met the realities of power, and speaks to the power of ideas in international relations, and their unexpected consequences. It is the story of a woman whose extraordinary career harnessed the power of expertise, which consequently swept her past some of the entrenched prejudice of the age, but also constrained her career. Yet it is also the story of the wishful thinking and blindness which expertise can engender, and the ways in which technical expertise is inseparable from its own perception. One hundred years after Sarah Wambaugh’s career in plebiscites began, the world is still struggling with the questions of democracy, expertise, and gender, which defined it.