In Colonial Suspects, Kathleen Keller contends that surveillance of suspicious persons in interwar French West Africa was indispensable to the state's efforts to maintain stability and suppress opposition. Officials relied on surveillance to remove potential threats: to deport foreigners, to repress Communist or pan-Africanist groups, to confiscate radical periodicals. Yet even as officials used surveillance as an instrument of colonial rule, Keller suggests, suspects’ activities and the illegibility of certain spaces limited the success of this strategy, reflecting the unsettled and incomplete nature of colonial power.

Keller builds on scholarship that explores how colonial states used data collection and policing in the exercise of power, and she adds new depth to our understanding of the French colonial state. Her signal contribution, however, is the internationalization of this history. By focusing on so-called ‘foreign suspects’ alongside French nationals and subjects of French West Africa, and by highlighting the importance of radical political ideas that circulated across borders, Keller usefully situates the history of interwar French colonialism in a global context.

Keller's introductory chapter outlines the book's main arguments, describes her sources, and engages with historiography. In Chapter One, Keller provides an overview of surveillance in French West Africa, tracing shifts in emphasis and approach during and after the First World War. In the 1920s, as radicalism increased in other parts of the empire and among colonial subjects in France, a ‘culture of suspicion’ emerged in French West Africa, prompting the surveillance of foreigners, travellers, educated Africans, and others who might oppose the colonial regime (50). Chapter Two describes the ‘messy everyday deployment of colonial power’ and explores police surveillance techniques and their limitations (85). Police in cities could use ‘discrete’ surveillance methods (like ‘shadowing’) only in European neighborhoods, while African neighborhoods remained inscrutable; in rural areas, officials had to depend on information from African allies.

In the remainder of the book, Keller examines the targets of colonial surveillance, devoting a chapter to each of the three major categories of suspicious persons identified by the colonial state. Chapter Three focuses on foreigners (who were neither French nor Africans from the colonies of French West Africa) and contends that these individuals accounted for a disproportionate number of suspects because ‘French police understood foreignness as a critical element of suspicious behaviour that threatened to destabilize colonial society as well as politics’ (89). In Chapter Four, Keller turns to French nationals who fell under suspicion in French West Africa because officials feared they might ‘usurp state authority or provoke negative images of Frenchness’ (122). In policing their behaviours, Keller concludes, officials worked to ‘shape a French community along specific class, legal, and moral lines’ and protect the idea that French superiority justified colonial rule (147). Suspects pushed back by using the rights and status afforded by their nationality in pursuit of their own goals. Africans of French West Africa, the focus of Chapter Five, also became suspects, especially when they engaged in political activities that could challenge French authority. Keller shows how the police used ‘surveillance and investigations’ with some success as instruments of repression against African political networks, but notes that Africans coped by operating underground, forming or joining new groups, and skirting government bans (152). A brief Conclusion recaps Keller's main points and comments on postwar shifts in police surveillance prompted by African nationalism.

This study has many strengths. It is filled with fascinating anecdotes about suspects which support most of the main arguments while also providing accessible and enjoyable reading. It offers new details about how the colonial state functioned on the ground in French West Africa. And most importantly, it shows how transnational intellectual currents, politics, crime, and travel shaped French West Africa in the interwar period. Although it is foregrounded in the chapter on foreign suspects, this thread extends throughout the book and Keller offers useful discussion of how national origin, race, class, and gender influenced surveillance.

Yet even as this study achieves a global frame, Keller is less successful at capturing the textures of life in interwar French West Africa or describing the larger communities to which these suspects belonged. More attention to local histories would help readers better understand the degree to which suspects were typical or exceptional, and what they might teach us about the experiences of the majority. It would also enrich the discussion, in Chapter Five, of African political networks, which is currently limited only to those groups and leaders that attracted police attention. This focus reflects the somewhat narrow range of archival files consulted; Keller might have been able to tell a richer, more nuanced story had she consulted additional materials in Dakar or Aix-en-Provence (files on the repatriation of indigents, for example) or carried out research in other West African archives.

In sum, this book is an excellent study of the colonial state's attempts to exercise power through surveillance and of the emergence of the ‘colonial suspect’ as a salient category. Students and scholars interested in the history of policing, of the French Empire, or of interwar colonialism in Africa will find it useful.