Introduction

Borders, walls and fences made a remarkable comeback at the turn of the millennium as they now underline one-fifth of the world’s dyads and delimit the territory of states, both failed and prosperous, democratic and authoritarian, scarifying every continent. In doing so, border walls contribute to reshaping mobilities and bodies, in a global world. Encompassing a heterogeneous set of structures built along 72 borders, they are both the manifestation of political fantasies and of an increasingly lethal reality.

Why do we care about walls?

Historically, as lines delineating two sovereignties, borders have been studied and considered as geographical markers of territorial control, state power and manifestations of national identities. Over the centuries, borders have become a central part of states' discourse on security, power and wealth. From a fixed material line, borders have evolved into mobile, pixelated and immaterial border zones (Sassen, 2015; Amilhat-Szary and Giraut. 2015; Balibar, 2004; Brambilla, 2015). While the functions of dividing, regulating and controlling borders have not changed, the places where they are established have multiplied (Balibar, 1996).

These transformations mark not only the way borders are managed by states, but also the way they are perceived, experienced and analysed by individuals and academics. Boundaries are changing, both theoretically and physically. The transformation of borders has led to a renewed interest in border research as a locus for the articulation of state sovereignty, the classification and sorting of individuals and as obstacles to the mobility of people (Salter, 2008). As a result, Border Studies have evolved along with their research focus: The border is no longer analyzed as a simple territorial line, but rather in terms of border zones (Anzaldua, 2012; Brunet-Jailly, 2007; Rosier and Wendl, 1999; Anderson and O’Dowd, 1999) with increased interest in the processes of bordering, debordering and rebordering (Popescu, 2011; van Houtum, Kramsch and Ziefhofer, 2005). Therefore, as borders have evolved, some states have chosen to fortify their border(s) with walls, the Berlin Wall being one of the best known, although it has since fallen. While some announced at the end of the 20th century the end of territories as a referent, of the nation-state as the central element of international relations, of sovereignty as the cornerstone of collective security in an increasingly global world, the importance of border walls has rather increased in the second half of the 1990s and since 9/11 (Vallet and David, 2012; Brown, 2009). Neither geographically circumscribed nor confined solely to a continent or region border walls have an impact on populations, exchanges and flows on all continents. Walls have created interstitial spaces of globalization where flows are slowed down, but not totally impeded, that define what globalization has become today.

These transformations of border perceptions and materializations have broadened the field of Border Studies, with the idea of walls gaining more traction and interest within academia. If we as academics can take the interest of our field of study for granted, asking the question “why are border walls interesting?’’ allows us to highlight three specific features of border walls that mark the interest of these structures.

First, border walls as the object of research allow for, and encourages, interdisciplinarity. As both physical and virtual manifestations of state power and ideology, border walls are not anchored into one discipline, but rather invite scholars to collaborate beyond disciplinary boundaries. While they divide populations or flows, walls also bring scholars together to produce more comprehensive, diversified knowledge allowing for a portrait of walls as they ar e; Multi-faceted.

Second, border walls studied here are inter-national? As mentioned earlier, walls are not limited to a geographical area and their construction often creates specific bi-national relationships between neighboring states, both in regional contexts and at the international level. Border walls are legitimized by ideological discourses that are reinvested in other states, they aim to hinder international movements (economic or human) and are rooted in the dynamics of globalization.

Finally, border walls are inter-identity. Studying border walls at the individual level allows for studies of individual movements, identity politics, gendered analysis and discourses. As contemporary structures with impacts at the micro and macro levels, border walls are more than simple structures; they are manifestations of many dynamics and studying them informs us on many contemporary issues.

The politics of words

From daily life discussions to international resolutions, words are powerful and often convey a meaning that is both literal and figurative. Throughout history, languages have evolved, with some concepts or realities being defined by more than one word within the same language. However, while all refer to the same dynamics, words may not convey the same image, for words are political tools. The words we use can empower, hurt, fuel change, divide or unite. It is important to be aware of the power of words when discussing realities such as borders, migration and international relations.

The main concept of this book is the border wall. While its definition might be viewed as simple, it is important to highlight what the contributors of this volume mean by “wall”. Furthermore, the word used to describe a bordering structure is often anchored into a political, ideological and regional background. In this volume, contributors use the words “wall” and "fence” interchangeably to refer to a bordering structure. While walls and fences can be used metaphorically, barrier’s have a more general sense of slowing down or getting in the way. Therefore, physical walls are defined as barriers with masonry foundations that are

flanked by boundary roads, topped by barbed wire, laden with sensors, dotted with guard posts, infrared cameras and spotlights, and accompanied by an arsenal of laws and regulations (right of asylum, right of residence, visas). We understand the word ’wall’ in the broadest sense, as a political divider that comprises complex technologies, control methods, legislative provisions and ‘securing the border’ discourse.

(Vallet and David, 2012)

Border walls are erected for a variety of reasons, but restricting migration is one of the most frequently cited reasons and one of the prevailing drivers for securing borders and building fences and walls. Aimed at controlling migration and movement on the peripheries of states, border walls are justified by othering discourses that tend to criminalize and dehumanize migrants by using terms such as “illegal aliens". The editors and contributors to this volume collectively decided to use the terms “undocumented”, “nondocumented” or “irregular” as referents to someone who enters a country outside of legal ports of entry or overstays a visa.

Grouping countries in regional blocs can be useful to highlight shared realities but can also contribute to a persistent lack of knowledge and awareness of country-specific dynamics. Furthermore, it perpetuates an imbalance of power between countries, the powerfuls being named and the less powerfuls being regrouped in regional groups and sub-groups. Throughout this book, all countries mentioned are named, and regional subgroups are divided, so as to bring forward the specific countries impacted by or actor of the policies discussed. For example, authors are not using “Northern Triangle of Central America”, but rather naming Honduras, Guatemala and El Salvador.