Borderlands have long been among the most dynamic places in the world. Recently, they have also emerged as one of the most dynamic sites of social sciences research. People living in borderlands often show extraordinary creativity in interacting with the ‘other side’ and in making use of the opportunities generated by differences in state regulations. The border gives some the opportunity to challenge the order of things on their side and to develop new modes of social integration across existing divides; it helps others to strengthen social identity by offering a new, centrally enforced, set of social ascriptions. Borders, in short, may be created to contain agency, but they often end up lending it new scope.

This is the perspective offered by this rich and focused volume on borderlands in the Horn of Africa. Even after many years of research into African borderlands, seeing borders as resources still seems to run against the grain of conventional thinking. Borders, the conventional wisdom claims, are artificial colonial inventions cutting through local polities and containing them into a national straightjacket. They are not resources for local agency, but a hindrance to it. From the preface to the volume, it seems the editors had some problems convincing their contributors of the value of the opposite approach, but in the end they have managed pretty well. The empirically and often conceptually rich contributions to the volume foreground how borderlanders make use of borders, without neglecting the negative impact that state borders can have.

In the introduction, the editors offer a useful literature review and a conceptual framework through which to read the following chapters. They differentiate four types of resources provided by borders, relating to the economy, to politics, to identity and to group rights, and offer a short description of factors they see as crucial in determining whether borders can be used as resources. While neither the typology nor the factors are likely to be the last word on the topic, they represent very useful empirically grounded tools for a comparative analysis of borderlands.

The ten chapters that follow are an essential read for every researcher interested in the Horn or in borderlands. They paint a vivid picture of the different ways in which the lives of ordinary people are influenced by state borders, and in which state borders are turned (or not) into a social reality by local agents. All chapters are written on the basis of a deep knowledge and in most cases familiarity of a specific border region; they are nuanced without the argument becoming lost in empirical detail.

Christopher Clapham's conclusion takes up the themes of the introduction. Where the editors have concentrated on borders as resources, Clapham points to the blind spots of such a partial analysis. Borders are always resources but they may simultaneously be constraints and sites of conflict. Through their existence and their specific history, they create realities that often stand in the way of better arrangements. If one tried to weigh the positive and the negative impact of borders for local people, what would be the result?

It is not the aim of Feyissa's and Hoehne's volume to answer this question. Instead, they offer a partial but extremely valid theoretical perspective sustained with detailed empirical data. Together with other recent work on borderlands in Africa, their work opens up a crucial debate that nobody interested in African political and social issues can ignore.