TERRITORIAL BORDERS AS INSTITUTIONS: Functional change and the spatial division of authority

Since the mid 1990s sociology has encountered what has often been referred to as the ‘spatial turn’ in the social sciences, in the slip stream of which also territorial borders have been re-discovered as objects of social research.¹ The newly developed interest in the study of borders was to some extent fuelled by new migration processes that followed the end of the cold war, to some extent it resulted from changing border regimes which accompanied processes of regional integration, most prominently in the case of the European Union (for an overview see Migdal, 2004). The emergence of border studies as well as their growing numbers therefore set a counter point to the euphoric claim of a borderless world as it has been put forward by many globalisation studies in the late 1980s and which gained momentum right after the downfall of the Berlin wall. Consequently, those studies concerned with the continuing existence of territorial borders, be it national or post-national, shed a critical light on the discourse about the ‘end of history’ that accompanied the breakdown of socialism. However, while there is an empirically rich body of literature on the social relevance of borders, much of this research, in particular with a macro-sociological focus, has been guided by theoretical concepts which emphasise the specific functions borders provide. These studies mainly identify borders with the provision of migration control and thus encounter specific challenges in addressing the relation between political actors, borders and territory. As the paper argues, by relying on such approaches it is not possible to ask how a particular border has developed over time and thereby also has changed the functions it provides. This possibility becomes particularly relevant when controversies or conflicts about border functions arise, as it was the case in 2011 when Denmark announced to reintroduce controls at the common border with Germany, as well as in the French-Italian rows about refugees from Tunisia during the Arab Spring. In both cases, organisational behaviour at the border and thereby the borders’ functions were contested.

For this paper, borders are taken as specific institutions which spatially separate the legitimate exercise of state authority. In this understanding, borders are institutionalised rules which specify which ruling organisation may legitimately claim the exercise of authority, and which allocate authority with reference to space. From this starting point, it is argued that borders cannot be properly understood if they are identified with historically specific functions, such as migration control, customs control or protection from foreign threats. Instead, such specific functions are regarded as being attached only to specific borders under specific historical circumstances, and as outcome of political conflicts and bargaining. Consequently the spatial allocation of authority is the stable institutional core of the border, which remains unaffected over time. In contrast to this feature, the specific functions which are provided by borders are expressions of the institution's flexibility.

The first section of the paper will discuss conceptualisations of borders that rely mainly on a definition with recourse to the specific function of controlling migration. Here, the argument will be developed that such an understanding faces problems in distinguishing migration control provided by borders from other forms of migration control provided by means of external cooperation or privatisation. In contrast to such approaches, the second part will develop an understanding of borders in reference to Georg Simmel's work, which does not rely on specific functions but on the relation between inside and outside, while the specific functions of borders are treated as specific political configurations of this relation. It is emphasised that borders allocate authority to specific ruling organisations according to space. Only because this element of borders is so deeply institutionalised that it is beyond the discretion of individual or corporative actors, it is possible to develop more specific rules which account for the border's specific function.

One of the most influential understandings of borders within the social sciences can be found within different theoretical schools ranging from post-structuralism, over neo-Marxism to sociological constructivism. It is the idea that borders are identical with instances of migration control that unifies authors from such different traditions. Within neo-Marxism Etienne Balibar sees contemporary society as characterised by the changing locus of borders so that they can be found at almost any place; they are ‘invisible borders, situated everywhere and nowhere’ (Balibar, 2002, original emphasis, similar: Walters, 2006a, b; Rumford, 2008). During the nation state's golden age, borders were localised only at the spatial edges of the state's territory. In contrast, contemporary borders are situated at all places where people are subject to controls that check the legitimacy of their stay. From Balibar's perspective, borders are characterised by three different attributes. They are first over-determined; second they have a polysemic character; and third, they are ubiquitous and heterogeneous. Whereas the concept of over-determination emphasises the importance of the international system in the sense that the border between two states from the same international bloc are more permeable than those between states from different power blocs (Balibar, 2002), the two later concepts refer to the border's functions and are theoretically more problematic.

What Balibar (2002) terms as ‘polysemic nature of borders’ refers mainly to their inherent selectivity, by which they differentiate the right of access between categories of people (see also Mau, 2010). In Balibar's words, this particular feature

From this perspective, Balibar's understanding departs radically from the view that the border is situated at the edges of a particular state's territory. But it is not merely the class divide which leads Balibar to the formulation of this new perspective. Also from processes such as the spread of international free trade agreements and cultural globalisation he concludes the last features of contemporary borders, namely their heterogeneity and ubiquity. These attributes emphasise:

Regarding the conclusion of omnipresent borders, Balibar is no unique case. Several other authors heavily emphasise the vivid character of borders, which would appear only in the process of controlling. It is the equation of control with the border that leads to the conclusion ‘that the supermarket checkout now resembles a border crossing or transit point where personal possessions, goods, and identities are routinely scrutinised’ (Rumford, 2008).

The equation of borders with controls cross-cuts disciplinary boundaries and theoretical schools. Such conceptualisations particularly dominate post-structural approaches in the tradition of Michel Foucault. According to Walters (2006b), the border must be understood not as ‘the defence of lines and fronts but as the surveillance of key nodes’. Consequently, the border in general has no substantial relation with spatial division between different territorial units of authority. Instead, those cases in which the practice of controlling borders arises at the demarcation line between two states is just one special instance of the more general concept of border controls. Because ‘the advent of digital technology and new systems of communication is transforming the architecture of borders’ (Walters, 2006b), the deeper essence of borders as a practice of power and discipline emancipates itself from the previous narrow spatial setting. This understanding of border becomes palpable

However, a closer look at the empirical phenomena which Walters lumps together as border controls reveals that their commonality is not so much in the ways controls are conducted, but that they are mainly targeted against unwanted transnational migration. Consequently, it reduces the practice of borders to the specific function of controlling migration. Whether controls are conducted at demarcated crossing points between two states, at airport check-ins or in embassies does in this view not defy the fact that all these measures are directed at the exclusion of undesired migrants and because of this common purpose would constitute the border. Such an understanding decouples the border from the territory and thus the location of controls becomes irrelevant.

Under the assumed equation of borders with controls, it is only consequent to identify the border everywhere, where such controls are conducted, independent from their territorial-political locus. For that reason, it is inevitable to conclude that

In the case of the European Union, this means that the border is also ‘situated in the Union's inside and the neighbouring states’ (Eigmüller, 2007, translation A.M.).

The argument developed in this paper does not put into question, that within the last two decades states have developed a variety of measures in order to prevent irregular migration, that these measures are applied already in countries of transit and origin, as well as within the territory (see among others Guiraudon, 2001; Lavenex, 2006). However, it is argued that identifying these controls as manifestations of the same instance blurs an important difference: both from the traveller's and the controlling state's perspective, the efficiency and sustainability of migration controls vary with the location of controls. Whereas carrier sanctions oblige private transport businesses to check for the travel papers and permissions of their travellers and thus aim at the prevention of undesired entries already at the place of departure, readmission agreements only come into effect once a person is detected on a state's territory and needs to be returned to a home or transit country. Opposed to these practices, employer sanctions aim at reducing the so-called pull-factors for irregular migration (Vogel, 2000). Not only that these different types of control involve different types of actors, some private, some public, some foreign and some domestic, but subsuming them under the headline of border control implicitly rests on the assumption that from the controlling state's perspective it is only of minor importance whether controls are deployed on the territory or ex-territorial. In more drastic words: it is a huge difference, if a particular state seeks to prevent somebody from entering its territory, if it wants another state to do so, or if it strives to get rid of someone who has already managed to enter its territory. In all these instances, selective controls are conducted, but they follow a different rationale, involve different actors and are accompanied by different challenges. Once a particular migrant has reached a state's territory he can rely on this state's legal system to provide some sort of protection against administrative and political decision which try to constrain his right to stay (Joppke, 1999; Guiraudon, 2000). The figures on successful and rejected asylum applications emphasise these differences: in 2009, the German Federal Office for Migration and Refugees processed 28,816 applications for asylum, of which it approved only 452, while from 11,360 rejected applications 9274 people were granted some sort of protection against deportation (Bundesamt für Migration und Flüchtlinge, 2011). Altogether 87,225 migrants who could not be deported despite lacking residence permit were officially registered in Germany, while only 7830 have been deported or repatriated (Bundesamt für Migration und Flüchtlinge, 2011). Unless it is assumed that there is some sort of ‘secret tolerance’ for the stay of irregular migrants, these figures indicate the challenges for migration control on the controlling state's territory.

Similar challenges emerge when migration controls are conducted at the territorial borders: here, asylum applications can be filed as well, unless safe third country or safe country of origin rules are applicable. If migration control is conducted abroad, the controlled person has substantially less possibilities to gain legal support; if they are conducted on the territory, the controlling states' discretion is strongly reduced by internal constraints. So as the border cannot be reduced to exclusion, but similarly marks the area of jurisdiction and political contestation, reducing the border to its exclusionary function systematically neglects that the costs of exclusion differ between the locations of exclusion. This, however, very likely influences the political agenda vis-à-vis borders. This holds as well for ex-territorial control measures. These occur either as visa obligations for nationals who are suspected to pose a higher risk of irregular migration, or as cooperation agreements with transit countries. The first method comes at a high political price because putting nationals of a particular country under the visa requirement usually negatively affects the controlling state's political relations with the country. While this is not a problem per se, introducing visa requirements might conflict with other imperatives of foreign policy, especially where visas are introduced for countries which constitute the controlling state's ‘backyard’. But also cooperation with countries of transit is in general politically expensive since these countries pose demands ranging from monetary compensation to migration quota for their own citizens in exchange for their prevention of transit migration. Thus ‘remote control’ in countries of transit constitutes a trade-off between preventing the irregular migration of third-country nationals and admitting migrants from the transit country. So while ex-territorial migration control is usually more effective, the political costs associated with these types of control are also substantially higher than those for controls on a state's ‘own’ territory. Although all these measures share the same object of controls, they substantially differ with regard to results and political costs, not to speak of rationales underlying the controls. However, these differences are systematically neglected by blurring them together as instances of the same phenomenon, namely the border. Thus it is also no longer possible to ask why different states pursue different strategies of control, i.e., which institutions they regard as more appropriate to provide the function of migration control.

These considerations imply that it is necessary to analytically distinguish between the border and the specific function under scrutiny. Consequently, the need arises to develop a concept of borders which does not rely on the specific functions it provides during a particular historical period, but is able to ask under which circumstances borders provide migration control, and under which circumstances alternative means and institutions are developed for this purpose.

Since it has become apparent that conceptualising borders by their specific functions leads either towards confounding the border with their functional equivalents, i.e., with other social practices or institutions that provide similar functions, or towards ignoring a change in the very institution, the lack of an appropriate theoretical framework becomes apparent. While the assumption of a tight relation between the border and its specific function (controls, protection) might at best hold for a short period under conditions of unconstrained states, for ‘post-national’ configurations of borders, this assumed relation has to be transformed into an empirical question. The term ‘post-national border’ refers to the ongoing tendency that, though being still borders of nation states, the regulation of border functions became more and more subject to decisions outside national forums of policy making. The last decades have seen a significant increase in the number and influence of regional associations of states, such as NAFTA, the EU or MERCOSUR which are becoming increasingly involved in the regulation of cross-border exchange, mainly about tariffs and goods, but in some cases even about trans-national mobility of people. Therefore, this development sheds even more doubt about the feasibility of isolating one specific function of borders and treating this as the institution itself. Thus, the questions – what is the social performance of contemporary borders under conditions of regional and supranational integration, and what new institutions are taking over responsibilities that have previously been associated with territorial borders? However, in order to answer these questions, an understanding of the border is required that is able to account for functional changes within a given institution.

Therefore, this section will show to what extent borders are the outcome of an institutionalisation process, but still leave room for institutional change. The peculiarity of the social phenomenon ‘border’ will be addressed, as well as we will emphasise the flexibility which allows for the possibility of institutional change. From that perspective, the following section will first develop the border as spatial type of relation between two units, thereby relying particularly on the work of Georg Simmel. After that, a brief historical account on the interaction between state formation and the production of borders will highlight the institutionalisation process of borders in order to address their relation with authority. Finally it is explored to what extent there is room for institutional change which alters the specific functions borders fulfil in different historical situations.

For Simmel, the boundary in general, irrespective of its spatial or non-spatial character, must be seen as a relation between two elements that entails a particular structure: ‘Each of the two elements affects the other by setting the boundary for it, but the substance of this interaction is the determination not to want or to be able to exert an effect beyond this boundary’ (Simmel, 1908 [1997]). Simmel regards social boundaries as the reciprocal self-restriction of influence. In his view, boundary making is an almost ubiquitous aspect of social reality insofar as it is of high importance because ‘everywhere, where the interests of two elements are directed at the same object the possibility of their coexistence depends on a border line separating their spheres within the object’ (Simmel, 1908 [1997]). This already hints at the relevance of boundaries for the exercise of authority. If a variety of organisations claims the exercise of authority, these organisations can co-exist only if there are rules that specify the cases under which a particular organisation might exercise its authority, i.e., their co-existence requires an allocation mechanism, which is the boundary.² In combination with Simmel's sociology of space, this understanding provides not a theory but a conceptual framework for the study of borders. Here, the spatial dimension of society is characterised by three features. First, similar to time, space itself is a mere formal condition of social processes, and neither cause nor effect (Simmel, 1908 [1997]). Second, specific institutions and figurations tend to be spatially shaped, and in some cases their spatial dimension is a necessary requirement for their sociologically relevant attributes. Third, from that perspective it is analysed what social institutions posses a tendency to take spatial form and how this form comes into existence. Finally, the specific spatial attributes of social facts produces feedback-loops on social realty. By anchoring institutions in a certain location and by providing them with a certain geometrical shape, they gain stability, are naturalised and in return structure social reality. This programme is also decisive for the way Simmel perceives borders:

The importance of this understanding can hardly be overestimated. For Simmel, the border involves two interwoven elements: first, it refers to the relation between those controlling the two areas; second, this relation has a spatial dimension. This type of relation can only exist because space, as its formal requirement, provides certain possibilities which are accessible for social processes, i.e., people recognise space and that they can somehow form it.

In Simmel's (1908 [1997]) understanding, there are five ‘fundamental qualities of the spatial form upon which the structuring of communal life relies’: it entails a specific kind of exclusiveness, it is divisible, it provides the ability to fix things to specific positions, as well as the ability to provide for distance and proximity. Finally, without space there would be no such things as movement and migration. In that regard, it is necessary to keep in mind that these qualities are not sociological relevant as such, but that certain social processes depend on these qualities (see also Lechner, 1991).

From these features, both exclusivity of space and its divisibility are of particular interest for a theory of borders since they constitute the difference between social boundaries in general – social groups reciprocally limiting, restricting their influence upon each other – and a border. First, space provides a high level of individuality in the sense that locations and even areas are unique, so that they might only be replaced by each other by abstracting from their peculiarity. Second, these places do not collide with each other. Although this consequence seems obvious, according to Simmel it has far reaching consequences: this feature

The ideal type of an object monopolising space is the state. The exclusivity of places goes hand in hand with the second attribute of space, its divisibility. Here, the identity of a segment, for example a social group, is expressed by the occupied place. In that regard the connection between the group and the location is essential in maintaining the group's identity vis-à-vis outsiders (Simmel, 1908 [1997]). That space can be divided and the thus established units can be assigned to specific structures accounts for the difference between borders and social boundaries in general.³ As has already been pointed out, boundary drawing is an essential feature of social reality, especially under conditions of distributional conflict. In Simmel's view, property rights, for example, would draw a boundary in the disposal over particular goods (see also Lamont and Molnár, 2002). Contrary to these forms of distributing control over a particular resource between different actors, borders are reciprocal restrictions of influences with the location in relation to a geographical line being the decisive rule to allocate this influence. It is this particular rule by which borders differ from other institutions, which allocate influence not according to space, but for example according to property rights. The spatial character of borders enhances their stability and validity. Thus,

From these considerations we can draw four conclusions for our purposes regarding the formal relations which constitute the border:

• 1.

  A border is a social relation between two social units which have an exclusive connection to space.

• 2.

  The relation is characterised by the reciprocal restriction of rights and of exercise of power.

• 3.

  This relation is spatially modelled in the sense that the influence and rights are restricted to the area on one side of the border.

• 4.

  The involved actors are aware of this relation.

Consequently, borders are spatial forms of reciprocal restriction between two elements which have a monopolising relation with their occupied place. This understanding of borders also implies the existence of a decision rule by which influence is allocated to one of these social groups. The existence of such a rule provides the possibility to treat borders as institutions.

Simmel's understanding of borders still entails a blind spot with regard to the units which actually draw the boundary. Due to this openness, Simmel's framework can be equally applied to categorically different types of borders, such as those of land property, of states, or of sub-state political units such as municipalities or counties. For a conceptualisation of political borders it is therefore inevitable to take into consideration the relation between the modern state and space. Consequently, the emergence of territoriality is an prerequisite for modern borders since it distinguishes the Westphalian state from pre-modern systems of authority (Ruggie, 1993). Already Max Weber defined ‘political community’ as ‘a community whose social action is aimed at subordinating to orderly domination by the participants a “territory” and the conduct of persons within it, through readiness to resort to physical force, including normally force of arms’ (Weber, 1922 [1978]) and thereby distinguished it from other systems of rule. In this regard, it is crucial that the community has a monopoly on the use of force, and that the territory is fixed. Unlike modern authority, pristine forms of government were based on kinship rather than on territoriality (among others Haas, 1982). Even where systems of rule covered a particular territory, this was not necessarily a fixed territory, as in nomadic societies. Here, ‘ownership meant, in effect, the title of a cycle of migration’ (Lattimore as cited by Ruggie, 1993: 149). And last but not least, medieval society provides the example for systems of rule that were not mutually exclusive but entailed overlapping, competing jurisdictions and authorities on the same space. ‘Briefly put, the spatial extension of the medieval system of rule was structured by a nonexclusive form of territoriality, in which authority was both personalized and parcelized within and across territorial formations’ (Ruggie, 1993). Usually within the same territory a king, local lords and the church simultaneously exercised political power. The difference between these systems of rule and the modern system of states and how they organise according to the principle of territoriality is palpable.

It was not before centralising tendencies triggered the development from local feuds to larger kinships and empires that early concepts of territoriality began to emerge. This process was characterised by military competition for power between local feuds and resulted in the accumulation of political power by particularly strong families. Once this step had been reached, the successful dynasty had accumulated enough power and force to put it beyond competition from the now subordinate lords. In return, the later ones were set back to a situation where they could merely compete with each other for influence at the strong dynasty's court, while striving for overall political power was beyond chances for success (Elias, 1939 [1976], see also Ruggie, 1993). As a consequence of this process, the feuds of the previously competing lords came under the authority of the powerful dynasty and thereby formed larger territorial agglomerations under a de facto monopoly of force. But even after these realms have been transformed into contiguous territories by several wars and acquisitions, they were not surrounded by clearly defined borders. Instead, they tended to become blurred at their edges. Here, the territories were usually not clearly defined and delineated from each other, but still characterised by overlapping jurisdictions and loyalties (Medick, 2006, see also Sahlins, 1989). Instead of border lines, marches prevailed and formed zones of passage and of ambivalent identities. However, the ideas of sovereignty and exclusive control over a contiguous territory were already at work, although they still lacked effective institutionalisation (Medick, 2006). And these ideas were at the core of the formation of borders in the modern world (Anderson, 1996).

As this brief historical detour has shown, the modern understandings of borders, authority and territoriality rested on each other in the course of development from medieval authority to the modern state.⁴

Considering borders as reciprocal restrictions of influence, the historic reconstruction provides the possibility to specify the type of influence, which is separated by the border, as exercise of authority. So borders assign the legitimate source of authority over people, or in Weberian terms ‘ruling organization’, according to the place of a person's stay, and not according to other criteria such as faith or lineage. This allocation of authority follows a particular rule: If one person is present at the location A, ruling organization 1 can exercise authority over that person. As long as this person is present at location B, the ruling organization 1 may not exercise authority over that person, but has to recognize that this falls under the domain of ruling organization 2. All locations A are separated from the locations B by a spatial line, over which both ruling organizations have reached an agreement, be it formal or informal.

It is noteworthy in that regard, that in this case it is only necessary that both ruling organisations reciprocally accept their counterparts’ domination over their respective territory, and that the border does not necessarily require legitimacy in the Weberian sense of indicating the relation between authority and subordinate people (Weber, 1922 [1978]). The emergence and institutionalisation of this rule marks the final stage in the process of state formation from medieval systems of authority to modern (nation-)states.⁵ However, because this rule is not transitional but stable, and because it is ‘beyond the discretion of any individual participant or organization’ but nevertheless structures their actions (Meyer and Rowan, 1977), it is justified to treat borders as institutions.

On a most general level, this is the institutional core of political borders. As institutions provide also a specific degree of flexibility which allows for institutional change without giving up their stable core (Thelen, 2002), so do borders. Where institutional change and development occurs, the rules that constitute an institution might vary both in number and in the degree of formalisation. Applied to the institution border, two directions of variation seem possible: subsequent rules might be attached to the core rule of separating the exercise of authority, and this set of rules might be more or less formalised. One example for the first variation can be seen in the recurrent rule that military deployed close to the border is usually regarded as aggressive behaviour. An example for the degree of formalisation, as provided by political geography, can be seen in the international agreements that regulate the practice of border demarcation (Prescott, 1965). Besides the question of the border's precise geographic location, formalised rules can also be developed and connected to the core idea in order to regulate the flow of cross-border processes. Such formalised rules might as well be established in order to assign different organisational behaviour to the border, for example of police and border guard forces. But the formalisation and institutionalisation of subsequent rules is not limited to the dimension of cross-border mobility. Also along the economic dimension, rules regarding the trans-national exchange of capital, commodities and services have been institutionalised over time at the border and since then undergone substantial changes. All such instances would indicate a particular state of borders, namely the institutionalisation of additional rules in relation to the core concept of spatially separating and allocating authority. However, the nature of these ‘subsequent’ rules differs from the border itself since the former ones are in principle negotiable, while the institution itself is too deeply enshrined, in particular in the case of the nation state, as a nation's identity is regularly expressed with reference to the territory. Consequently, they are not formalised but taken-for-granted institutionalised rules (Bach, 2010). Since a nation state's borders constitute its territorial existence, they are not negotiable because this would affect the state's core rationale and at the same time it would undermine the nation's myth as an always existing community occupying a particular territory (see Anderson, 1985). But also in multinational states, border, territory and the sovereign exercise of authority rest on each other, so that here as well the spatial separation of authority is an absolute condition for the existence of the state and hence withdrawn from being politically put into question.

Thus two principle elements of borders can be distinguished: the border as the institutionalised separation of the exercise of authority and the border as an object of political regulation and decision making. The first element comprises the border's territorial dimension and relates to its basal function for constituting the nation as well as the state's territory and entails the taken for granted, not negotiable element. In particular the border's location is beyond the reach of political decisions, as well as the understanding that the border constituted an outside which is as well withdrawn from the ‘own’ state's political and administrative rule. Contrary, the border's second element comprises those rules which specify organisational and individual behaviour at the border and which are institutionalised by political decisions. Consequently the second element accounts for the variable part of a particular border's institutional configuration. By distinguishing both features, it is possible to relate the institutional design of borders to the interests of political and societal actors. Only in this perspective, particular borders and their regulation can be traced back to actors’ expectations regarding the performance of these borders. Under these circumstances, the supposed relation between the border and its specific performance is transformed into a relation between the institution border and actors who are interested in the border performing specific functions. Insofar the historical development of specific borders and the institutional change they have undergone also implies that new rules have been attached upon the border's institutional core. Thus the functional change of borders for trans-national mobility can be traced back to different rules about border controls. Unlike today, in late nineteenth- and early twentieth-century Europe, borders performed, besides their economic function, mainly the function of preserving a country's military by establishing exit controls to prevent conscripts from avoiding their military service (Sikora, 1996; Bröckling, 1998). This function was achieved by the institutionalisation of subsequent rules on border controls. It was not until the aftermath of WWII that immigration became a main concern of border controls, which was achieved by establishing rules about the necessary residence permits and visas to be eligible to cross these borders. And vice versa, the provisions of the Schengen Agreement and the European Treaties abolished exactly these rules at the common borders between the EU's member states. Consequently, the controversy between the EU and Denmark in spring 2011 focused both on the rules attached to the common border between Denmark and Germany and on the competence to decide on these rules. However, in none of these cases the core principle of the border as spatially separating the legitimate exercise of authority was affected; subject to change were only the specific rules that have been attached to the already established institution. As can be seen from the Schengen aquis, the contractual foundation for the dismantling of border controls within the European Union, the notion of the border as separating the jurisdiction between the EU member states was left completely unaffected. Instead, the Schengen acquis determines a change of organisational behaviour since the member states agreed that their respective border guard and custom authorities refrain from controlling cross-border travel at stationary border crossing posts, as well as the agreements specify what national police forces are allowed to do in border areas. So the Schengen agreement deprived the borders between the EU member states of their function to control cross-border mobility of people. However, the existence of the border between those states was left unaffected. Once a traveller has crossed an intra-European border he becomes subject to the respective national law; and the organisations responsible for implementing the provisions of the Schengen agreement are still national organisations. What is more, the Schengen agreement does not touch upon the exercise of authority. Therefore, national administrations remain in charge as well as national jurisdiction is unaffected. So as the member states do not disappear within European integration, so do their borders. What has been changed are specific functions of borders according to political debate and decisions between the involved nation states and supranational organisations.

Consequently, the sociological analysis of borders refers to the politics and policies on borders.

Borders are not identical with the specific functions they perform at a particular historical period. To assume such an identity systematically prevents from asking how borders are subject to social change. Depending on the specific type of performance that is highlighted by researchers in order to qualify borders, they tend to coincide with other institutions that provide a similar function. But it is not only the lack of ability to separate between the institution and its function; also the spatial dimension of borders is neglected once they are reduced to the provision of selective controls. Departing from this notion, an institutionalist account, inspired by Simmel's sociology of space, provides the ability to distinguish the core concept of the border as separating the exercise of authority between different ruling organisations from the historical contingent parts, which are subject to political decisions and negotiations. This understanding of the institution border enables us also to shed new light on two distinct debates, namely about the relation of borders and controls, and about the relation between borders and post-national political bodies.

From this point of view, the discussion about borders and controls can be restated in terms of interests in controlling flows, mobility, and border crossing processes. The absence or presence of border controls as well as the way in which they are conducted results therefore from the negotiation of formalised institutional rules.

From this perspective, we can also re-approach the empirical phenomenon of migration control and the question where in relation to the territory such controls are conducted. As the border marks not only one possible site for conducting these controls, but also delineates the destination state's territory, it constitutes the area where this state's laws are applicable, which in return limit the executive's discretion vis-à-vis irregular migrants. Consequently, besides being potential means of migration controls, borders constitute at the same time some sort of ‘safe haven’ for refugees. Only if we take this Janus face of borders into account, we can understand why states are so creative in developing alternative means of migration control. Then, control procedures in the course of visa applications, as well as cooperation with countries of transit appear as ex-territorialised means which thus avoid the legal constraints at work on the controlling state's territory. By these measures, the eligibility of a particular migrant to enter the country of destination is established already prior to his or her arrival at the border. Such a perspective, however, is only possible if we distinguish the border's function from the institution itself and conceptualise the later one with reference to the controlling state's territory.

In a similar way, the framework proposed here can be applied in order to analyse how post-national political bodies transform and determine national borders (exemplary Zielonka, 2002). In the case of the European Union, the negotiable elements of national borders are dealt with not only on the level of individual states, but also within new, international bodies of decision making. Not only have several competences been transferred partially to new venues of negotiation, but also new political actors emerged, and policy areas that have previously been subject to national regulation, are becoming matters of multi- and supranational concern (Hix, 2005). This gives rise to new and more complex constellations. Within the European Union neither the nation states nor their borders have vanished, but the institutional design of these borders is now subject to formalised rules which have been developed on an EU-level with supranational actors and other member states involved in the decision-making process. Consequently the emergence of post-national borders builds on the core rule of borders as reciprocally separating the exercise of authority. What has changed is not this core rule, but that the political decision on and the formalisation of subsequent rules, which are attached to this institution and determine its functions, is no longer at the disposal of individual member states. However, the emergence of this new constellation is only possible because at the heart of borders still remains the strongly institutionalised idea of separating the exercise of authorities, which is beyond the discretion of political actors involved in the decisions about their functions.

Andreas Müller is a researcher fellow at the Federal Office for Migration and Refugees. His recently finished doctoral thesis focuses on the transformation of national borders by European Integration, and of external EU-borders by the European Neighbourhood Policy.