I. Making the Community Visible to the “citizens of Europe” ^{Footnote 43}

The project of establishing an area without internal borders has been at the core of European integration since the Treaty of Rome.^{Footnote 44} The principal reasons for abolishing border controls between Member States were economic considerations; the free movement of goods, reduction of indirect costs, and an increase in competitiveness were considered necessary measures towards the establishment of a common market. However, already in the 1960s and the 1970s the abolition of border controls between Member States went beyond the economic sphere and was explicitly linked to political integration. By doing away with border controls between Member States, the Community ought to be made visible to the “man in the street,” the ordinary citizen of the Community.^{Footnote 45}

Although the Commission drafted several proposals that envisaged reducing formalities at internal borders in the 1970s, Member States considered these proposals as going too far and systematic checks at borders between Member States remained in place.^{Footnote 46} However, secondary legislation, adopted to give effect to the provisions on the free movement of the nationals of the Member States, did limit the extent of such checks. In Pieck, the CJEU ruled that “any formality for the purpose of granting leave to enter the territory of a Member State which is coupled with a passport or identity check at the border, at whatever place or time and in whatever form” would amount to an “entry visa or equivalent requirement” and would thus be prohibited.^{Footnote 47} Border guards may not inquire about the purpose and duration of stay or the financial means of the EU citizen before permitting entry.^{Footnote 48} And although Member States were still permitted to carry out identity controls, the Court limited these controls: When identity controls take place at the time of entry into a Member State’s territory, they constitute a barrier to free movement when carried out in a systematic, arbitrary or unnecessarily restrictive manner.^{Footnote 49}

The key documents on abolishing border controls in the 1980s were the Commission’s 1985 White Paper on the Creation of the Single Market and the Single European Act. Although the White Paper did not offer significantly more than what the Treaties and the case law of the Court of Justice had already provided for,^{Footnote 50} it introduced a subtle but remarkable change of rhetoric. Whereas previous policy documents sought to change the mode of border controls, the White Paper questioned the very existence of border controls. The Commission made clear that the objective of the White Paper was not merely to ease existing border procedures “but to do away with internal frontier controls in their entirety.”^{Footnote 51} For this, the Commission advanced two sets of arguments: The first based on a market rationale, the second on a political rationale. Both rationales entailed specific arguments and assumptions about the market, competition, and modes of integration, as well as distinct conceptions of space.

Under the market rationale, the Commission advanced economic arguments, stating that “[t]he reason for getting rid entirely of physical and other controls between Member States is not one of theology or appearance, but the hard practical fact that the maintenance of any internal frontier controls will perpetuate the costs and disadvantages of a divided market.”^{Footnote 52} Border controls were conceived as inefficient means of controlling substantive policy domains, such as public health, veterinary inspections, VAT collection, and transport safety, which could be more efficiently governed through harmonization, administrative cooperation, and, if necessary, spot checks.^{Footnote 53} The reasoning behind this rationale was formal, technical, and bore an aura of necessity. It translated physical border controls into economic figures and calculated their direct and indirect costs.^{Footnote 54} It argued that the abolition of controls was to take place through harmonization and the use of technical bodies, such as the European Standardization Organizations.^{Footnote 55} And it presented the need to do away with border controls as the inevitable result of structural changes in the global economy, necessary to maintain economic competitiveness on a global scale. The specific conception of space is that of a market, a synthetic formal space that is governed by technocrats and rationally ordered to achieve specific objectives —such as, higher competitiveness, efficiency, and reduced costs.^{Footnote 56} In this market space, the rationale for abolishing border controls is functional: It is a means to realize the internal market – and not an end in itself.

Yet, the drafters of the White Paper were aware of the weak legitimacy of the market rationale and the need for a broader political narrative.^{Footnote 57} Thus, the White Paper linked the abolition of border controls to the discourse of constructing European citizenship. The crucial difference between the market rationale and the political rationale is that while behind the market rationale the abolition of border controls is a means to establish the internal market, the abolition of border controls in the political rationale is an end in itself. Borders are constitutive of political communities and, more precisely, of liberal conceptions of citizenship.^{Footnote 58}

The European Council meeting at Fontainebleau in June 1984 had already considered it essential to “respond to the expectations of the people of Europe by adopting measures to strengthen and promote its identity and its image both for its citizens and for the rest of the world.”^{Footnote 59} The Council established an Ad Hoc Committee on a People’s Europe, which recommended the implementation of measures that facilitate the freedom of movement of Community citizens across intra-Community land borders as the easiest way to provide the citizens of the Member States with “tangible benefits in their everyday lives.”^{Footnote 60} Only three months afterwards, the Commission in its White Paper adopted a similar line of reasoning, when suggesting the full abolition of intra-Community borders:

And it continued:

There are two aspects to the White Paper’s terminology. First, although no Community legislation existed which requires the abolition of controls at intra-Community borders, the White Paper nevertheless states that the principle of free movement mandates the abolition of border controls. This is essentially a legal argument. However, the White Paper does not explain the legal reasoning that mandates the abolition of border controls, but rather employs legal terminology to advance an argument about European integration. This is linked to the second aspect. Free movement is couched in a narrative that construes border controls as material obstacles that prevent citizens from seeing the progress of European integration. If border controls, as physical outward signs that divide different Member States, were removed, citizens would be able to see a single Community instead of different national jurisdictions. The objective of abolishing border controls in the White Paper aimed at transforming the way citizens would see the Community.^{Footnote 63} Like a state, the Community requires a material manifestation to become real in the political imagination of citizens.^{Footnote 64} Interestingly enough, the terminology of the White Paper was not merely a bold pitch of Brussels-based elites, but reflected and dwelled on prior historical events; in particular, as we argue below, on the protests of truck drivers against border controls in several Member States that occurred one year before the publication of the White Paper.^{Footnote 65}

II. Schengen as ‘Test’ Laboratory for the Internal Area Without Borders

The Single European Act was adopted to enable the completion of the internal market as envisaged by the White Paper. It inserted Article 8a into the European Economic Community (EEC Treaty)Footnote ⁶⁶, which defined the internal market as “an area without internal frontiers in which the free movement of goods, persons, services and capital is ensured in accordance with the provisions of this Treaty.”^{Footnote 67} However, disagreement arose as to the definition of the internal market as an area without internal frontiers. This is best illustrated by Margaret Thatcher’s speech at the College of Europe in 1988. While the UK government supported the neo-liberal idea of borderless trade, Thatcher made clear that she regarded it “a matter of plain common sense that we cannot abolish frontier controls if we are also to protect our citizens from crime and stop the movement of drugs, of terrorists and of illegal immigrants.”^{Footnote 68} The idea that the lifting of internal borders triggered a security question, was not exclusive to the UK. The White Paper itself recognized a need for “alternative means of protection for controls at the internal borders and to strengthen those already existing.”^{Footnote 69} However, where the UK and other Member States differed was where and by whom this security concern was to be addressed.^{Footnote 70}

In June 1989, the Madrid European Council approved a work program for the establishment of an area without internal frontiers, the so-called Palma Document, but noted the political divergences “on the interpretation and scope of the relevant Treaty provisions inter alia 8A EC and the obligation flowing therefrom . . . and where the competence for taking decisions and action lay [to adopt the measures deemed necessary to allow for the abolition of internal borders].”^{Footnote 71} The way forward was intergovernmental. Under the responsibility of the immigration ministers, work started on a Convention on crossings at the external frontiers of the Member States.^{Footnote 72} This resulted in the Member States reaching agreement in June 1991. Although a Declaration attached to the Convention stated that it was signed “with a view to achieving the objectives of Article 8a [EEC],” that same Declaration made clear that it did not “contain any express or implicit obligation upon Member States concerning controls at intra-Community frontiers.”^{Footnote 73} Ultimately, disagreement between the UK and Spain over the status of Gibraltar prevented the Convention’s signature.^{Footnote 74}

It was the lack of progress within the Community framework that allowed Schengen, as a parallel initiative to abolish border controls between continental Member States, to gain practical and legal significance. With the signature of the Schengen Agreement in June 1985, Germany, France, and the Benelux countries took the principled decision to abolish border controls between their territories. Subsequent accession agreements were signed with other EU Member States, except the UK and Ireland. The Schengen Agreement set out some immediate measures; for instance, the easing of formalities at border controls,^{Footnote 75} reinforcement of cooperation of police authorities, and approximation of rules.^{Footnote 76} The actual lifting of controls at internal borders, however, was made dependent on the adoption of a set of common rules in the field of external borders, migration, asylum, and police cooperation. The adoption of these common rules aimed to offset the alleged security deficit that would result from the abolition of internal borders and was foreseen by January 1, 1990.^{Footnote 77}

It took five years to adopt these so-called “flanking measures” in the Schengen Implementing Convention (CISA). Unlike the Schengen Agreement, the CISA included the abolition of border controls as a legal obligation and not merely as an objective to be realized in the future. In March 1995, all Schengen participating states, with the exception of France, had abolished controls at their internal borders.^{Footnote 78} Two years later, the Member States, in the Treaty of Amsterdam, decided to incorporate the Schengen acquis in the EU legal order.

Although the development of Schengen under international law can be formally regarded as separate from the internal market project and thus EU law, the two cannot be regarded in isolation.^{Footnote 79} They took place at the same time, involving the majority of Member States and, most importantly, shared an underlying rationale that transcended considerations of an economic nature. Three examples illustrate this: The events that eventually resulted in the adoption of the Schengen Agreement in 1985, the scope of the CISA, and the measures adopted to implement the CISA.

First, the origins of the Schengen Agreement lay in a “symbolic initiative”^{Footnote 80} taken by Germany and France to relax checks for car drivers, which led to protests by French, German, and Austrian lorry drivers, who continued to be stopped at internal borders. Although economically motivated, these protests cannot be reduced entirely to a market rationale: The protests were widely regarded as targeting controls that “should have ceased to exist.”^{Footnote 81} These protests eventually resulted in the conclusion of the Saarbrücken Agreement, which formed the blueprint for the conclusion of the Schengen Agreement one year later. ^{Footnote 82}

Second, the preambles of both the Schengen Agreement and the CISA explicitly refer to the objectives of the European Community. The Schengen Agreement stated that “the ever closer union of the peoples of the Member States of the European Communities should find its expression in the freedom to cross internal borders for all nationals” and that the removal of obstacles to free movement would “strengthen solidarity between them.”^{Footnote 83} The CISA added a specific reference to the Single European Act and the internal market as an area without internal frontiers. It also affirmed that it would not prejudice the objectives of the European Community. The Schengen process soon came to be regarded as a “laboratory” for a common European space without borders,^{Footnote 84} a form of enhanced cooperation avant la lettre, and was broadly understood as part and parcel to the construction of an area without internal borders.^{Footnote 85} Commission officials and representatives of Member States endorsed the view that the Schengen cooperation concerned Community boundaries, which is also confirmed by the definition of alien under the CISA as anyone not holding the nationality of a Member State.

Third, the explicit links to the European project already show that the Schengen acquis sought to create more than just an internal market. This is particularly obvious from one of the key decisions adopted by the Schengen Executive Committee in April 1994 for the implementation of the CISA, concerning the reduction of obstacles to traffic flows. The brief and single operative paragraph of the decision simply states that material structures at border crossing points must be removed, as they constitute obstacles that hinder free movement and traffic across internal borders.^{Footnote 86} However, the Annex to the Decision goes much further than merely ensuring unhindered crossing of the border and suggests to either dismantle entire border structures and facilities or putting them to another use. This can only be understood when seen in the light of the objective to transform the sensory perceptions of citizens of the Union as a single spatial entity.

III. Meeting Mr Wijsenbeek

The Maastricht Treaty repeated the objective of establishing an internal market as an area of free movement without internal frontiers.^{Footnote 87} Yet, despite this unambiguous wording and the objective to complete the internal market by December 31, 1992, the failure to adopt the External Frontiers Convention meant that internal border controls were not lifted by this date.^{Footnote 88} Frustrated by the lack of progress, a group of integration-minded Members of the European Parliament (MEPs) tried to force a judicial breakthrough by seizing the CJEU of the matter. In previous situations of political deadlock, the CJEU had proven instrumental in giving full effect to the provisions of the Treaties and strategic litigation has been at the basis of some of the classic cases of EU law.^{Footnote 89} The case that eventually reached the CJEU, by way of preliminary reference, was that of Dutch MEP Floris Wijsenbeek. Upon arriving from Strasbourg at Rotterdam airport, which only operated intra-Community flights, Mr. Wijsenbeek refused to show his passport. He was fined for violating Dutch immigration law and the Dutch Court of Appeal eventually referred a straightforward set of questions to Luxemburg: Do Articles 7a, —now Article 26 TFEU— and 8a —now Article 21 TFEU— of the Treaty establishing the European Community (EC Treaty) preclude Member States from imposing an obligation to present a passport at intra-Community borders?^{Footnote 90}

The standard account of the Wijsenbeek decision is that the Court held that neither Article 7a nor Article 8a of the EC Treaty had direct effect, since both Treaty provisions required the adoption of implementing legislation. The CJEU therefore concluded that, absent any harmonized rules on the controls of external borders, visa, and asylum, Member States retain the right to carry out border controls.^{Footnote 91} This account, however, overlooks the legal nuances of the decision.

There is an important part of the judgment that focusses on the role of Union citizenship. Both the Commission and Advocate General Cosmas made a clear distinction between free movement rights in the market sphere —Article 7a EC Treaty— and citizenship —Article 8a EEC Treaty. The Commission argued that while free movement in the market sphere requires the adoption of harmonization measures on external borders, the right of citizens to move freely across borders is “recognised directly in that provision, without any reservation and without the slightest scope for the exercise of discretion.”^{Footnote 92} Although the Commission argued that the right of citizens has “incontestabl[y]” direct effect, the Commission considered that it may be subject to limitations foreseen in the Treaty; as long as no harmonized rules on external borders were adopted and put in place, the Commission argued, Member States could require Union citizens to show valid travel documents at the internal borders.^{Footnote 93}

This distinction between free movement rights that pertained to the market sphere and free movement rights that pertained to the political sphere, in the context of border controls, is even more pronounced in the Opinion of the Advocate General. Advocate General Cosmas argued that the former “have established a functional possibility for nationals of the Member States . . . with a view to the creation of a common market, the objective of which can only be to permit persons to pursue their economic activities in optimum conditions.”^{Footnote 94} In other words, the abolition of border controls —and the rights linked to it— in the market sphere are functional to creating the internal market. By contrast, citizens’ rights to free movement differ categorically from the rights in the market sphere; they constitute, as Advocate General Cosmas argued, “a right of a different kind, a true right of movement, stemming from the status as a citizen of the Union.”^{Footnote 95} He continued:

Thus, the freedom of nationals of Member States to enhance their economic benefits would not be “seriously threatened” by the requirement to show a valid travel document at the border; by contrast, the freedom of Union citizens would be seriously infringed by the requirement to show a travel document at the border.^{Footnote 97} Why? Because the “freedom to cross borders is in itself an important constituent of the citizen’s right to move freely, and not simply a means of achieving the common market. Moreover, recognition of the possibility of moving —in principle— unchecked within the geographic area corresponding to a legal order is inherent in the status of citizen covered by that legal order.”^{Footnote 98} Similar to the Commission’s legal opinion, Advocate General Cosmas concluded that the overriding public interest in the absence of harmonized rules on external borders justified limiting a citizen’s right to free movement by checking travel documents at the border.^{Footnote 99}

Against the background of the elaborate arguments of the Commission and the Advocate General, it is interesting to see what the CJEU did and did not say in its short reply to the questions put before it. It is interesting to note the difference between the Court’s arguments on free movement in the market sphere and in the political sphere. As regards the market sphere, the Court followed the Commission and the Advocate General and unambiguously held that no automatic obligation arises from Article 7 EC Treaty to abolish border controls after December 31, 1992, because it presupposes harmonization of rules on external borders.^{Footnote 100}

As clear as the Court’s argument was in regard to the market sphere, as enigmatic was its ruling in relation to Union citizenship. The Court merely stated that as long as EU legislation on external borders was absent “the exercise of those rights presupposes that the person concerned is able to establish that he or she has the nationality of a Member State.”^{Footnote 101} In the following paragraph the Court added that even if under Article 21 TFEU Union citizens were to “have an unconditional right to move freely within the territory of the Member States,” which indeed it later held to be the case in Baumbast,^{Footnote 102} Member States retained the right to carry out identity checks at the internal frontiers of the Community.^{Footnote 103} The Court thus argued that Article 8a EC Treaty, as was submitted by the Commission, can be justifiably limited. While it referred to the declaration on Article 7a EC Treaty, that the date of December 31, 1992 does not create automatic legal effect, it did not refer to the same declaration on Article 8a EC Treaty^{Footnote 104} nor to the UK and Ireland’s arguments that Article 8a EC Treaty does not have direct effect. As it did in earlier cases,^{Footnote 105} the Court made a distinction between the existence and the exercise of free movement rights of citizens.^{Footnote 106} It clearly stated that the exercise, and not the existence, of citizens free movement rights presupposes EU legislation on external borders.^{Footnote 107} The CJEU thus recognized, albeit implicitly and subject to the conditions of flanking measures, such a right to free movement based on the Treaty’s provision on Union citizenship.

It is important to realize that the Court upheld the distinction between free movement rights in the market sphere and free movement rights in the political sphere. By connecting the latter to the abolition of border controls the Court created a link between Maastricht’s —intergovernmental— third pillar on justice and home affairs and its —supranational— Community pillar and confirmed the link between the abolition of border controls and Union citizenship.

I. Amsterdam: Establishing the Area of Freedom, Security, and Justice

At the time Court delivered its judgment in Wijsenbeek, in autumn 1999, the Treaty of Amsterdam had already entered into force. The Court’s reluctance to make a bolder move and explicitly recognize the direct effect of the free movement of EU citizens may be explained from its intention not to upset the comprise negotiated in the Amsterdam Intergovernmental Conference, which incorporated the Schengen acquis into the EU legal order at the cost of a variable geometry in this area.

Still, the Court could have simply accorded direct effect to the absence of internal frontiers. In quite a few internal market cases the Court was not deterred by the absence of harmonizing measures. To the contrary, legislative inaction was often at the basis for according direct effect to provisions of primary law.^{Footnote 108} The argument that this would have resulted in a “regulatory gap” does not convince, because the third pillar did provide the Union with powers in this field, and alternatively such powers were implied in the legal basis provisions on the free movement of persons.

More importantly, the objective of the strategic litigation in Wijsenbeek—to abolish controls at internal borders—had already materialized when the Court of Justice delivered its decision in September 1999. The Treaty of Amsterdam had entered into force on May 1, 1999 and incorporated the abolition of border controls into the EU legal order. It did so in a twofold way.

First, the Treaty of Amsterdam incorporated the Schengen acquis into EU law through Protocol No. 2,^{Footnote 109} thus “bringing to life the decades-old vision of a Europe without internal border controls.”^{Footnote 110} It obliged the Council to adopt common measures on asylum within five years, external borders and visa for third-country nationals that aimed at ensuring the free movement of persons.^{Footnote 111} Until that moment, however, the compensatory measures of the Schengen acquis were considered as acts of secondary legislation.^{Footnote 112}

Second, the Treaty of Amsterdam established a link between citizens and the Schengen acquis by including the area of freedom, security and justice (AFSJ) as an objective of the Union into the Treaty framework.^{Footnote 113} The establishment of the AFSJ was based both on a market rationale and a political rationale. On the one hand, the measures on migration, asylum, visa and borders clearly stand in function of the economic dimension of the free movement of persons.^{Footnote 114} In two cases brought by the UK against the Council, the Court of Justice ruled that a Member State can only participate in a measure of the Schengen acquis, if it accepted the area of the Schengen acquis on which that measure builds. As the UK had not accepted the rules on abolishing internal border controls, it could be validly excluded from Frontex, the European Border and Coast Guard Agency, and the Regulation on security features in passports.^{Footnote 115}

On the other hand, the establishment of an AFSJ clearly goes beyond the internal market rationale. The Turin European Council, which constituted the opening session of the Intergovernmental Conference, had identified the objective of bringing “the Union closer to its citizens” as one of the central themes for the Conference and had grouped the substantive policy fields of the AFSJ under this heading.^{Footnote 116} The Treaty of Amsterdam inserted the aim to develop the EU as an AFSJ in which the free movement of persons is guaranteed as a new Union objective in the Treaty framework, in addition to the internal market objective.^{Footnote 117} In line with this, the Tampere European Council Conclusions, the first five-year strategic plan for the development of the AFSJ, described the area as “a project” that “responds to the frequently expressed concerns of citizens”, “has a direct bearing on their daily lives” and freedom as the “right to move freely throughout the Union.”^{Footnote 118} The title of Tampere’s successor program, the Stockholm Programme confirmed this political dimension, promising “an open and secure Europe serving and protecting the citizens.”^{Footnote 119}

A common critique of this political dimension is that security constitutes the overriding imperative, thus crowding out freedom and justice. It has been argued that the incorporation of the Schengen acquis into the EU legal order “Schengenized” the Union and codified the narrative that free movement internally can only be achieved by more restrictive compensatory measures.^{Footnote 120} While this is certainly true, we caution to consider the AFSJ only from a security perspective. By the Court’s own logic in Wijsenbeek, what is required is simply a framework for the management of the external borders; it did not impose any additional conditions as to the substance or effectiveness of these rules.^{Footnote 121} Moreover, the lifting of internal border controls was deliberately premised on the idea of mutual recognition and limited harmonization, the so-called flanking measures. This logic remains present until today in the distinction between Schengen developing measures and other measures covered by Title V in the TFEU on the AFSJ. A lack of progress in AFSJ policy fields, such as the Common European Asylum System or criminal justice cooperation cannot be invoked to question the absence of border controls —although it might negatively affect Member States’ views on a borderless Schengen.

Like earlier Commission and Council documents on the abolition of border controls, which were discussed in the preceding section, the notion of citizen refers to Union citizens in a political register—and not as a formal legal status. The Treaty of Amsterdam did not link the AFSJ to the formal legal status of Union citizenship, a link that was established only explicitly in the Lisbon Treaty, but the notion of citizen also went beyond holding the nationality of one of the Member States. After all, the objective of including the AFSJ into the Treaty of Amsterdam was not merely to abolish border controls but “to develop [the EU] more rapidly into an area of freedom, security and justice.”^{Footnote 122} Thus, the inclusion of the AFSJ into the Treaty of Amsterdam sought not merely to construct a “new kind of policy whole,”^{Footnote 123} but also to construct a common area. Had the Treaty drafters sought to establish merely different policy fields, they could have used freedom, security and justice tout court. However, they included the spatial notion of area and linked these three values to the area. By including the notion of area in the AFSJ, the Treaty drafters shifted the rhetoric of integration from a negative —absence of internal border controls— to a positive —construction of a common area— semantic.

The AFSJ as a common area of the Union entails two features. First, the AFSJ constitutes a geographic space where border controls are abolished and citizens can move freely without being subject to border controls. In order to establish and maintain this geographic space where internal border controls are abolished, the power of the EU institutions was enhanced: The Commission was given increased powers of initiative in all areas of the AFSJ, the Justice and Home Affairs Council preserved institutional unity across the different policy domains, and the European Council in Tampere in October 1999 set out concrete policy objectives to develop the AFSJ.

Second, the area as geographic space is normatively qualified by the values of freedom, security and justice. This dual dimension of the AFSJ—a concrete geographic space and a normative space—points to a deeper meaning of the notion of citizen in the political register: The relation between citizenship and space. For Hanna Arendt, the realization of freedom and equality—the hallmarks of modern citizenship—as a tangible concrete reality is the result of a decision taken by a political community to accord to its members equal rights: “We are not born equal; we become equal as members of a group on the strength of our decision to guarantee ourselves mutually equal rights.”^{Footnote 124} As a community is necessarily located somewhere, the realization of freedom and equality requires spatial boundedness, which, as Arendt argued, was “especially clear for the greatest and most elementary of all negative liberties, the freedom of movement.”^{Footnote 125} If Arendt’s argument is transposed to the AFSJ: The abolition of internal border controls and the creation of a common external border established a territorially bounded place in which free movement is realized as a tangible reality. Hans Lindahl argues that “values are a constitutive feature of territoriality”; by deciding which values are legally relevant and which values are not, a community —in this case: the ensemble of Union citizens— relates to that space and creates its “own place.”^{Footnote 126}

To be clear, it is only in the abstract that the geographic and the normative features of the AFSJ as a legal place can be held apart. A legal place always involves territorial boundedness and at the same time a decision which values are legally relevant in that place. Therefore, how a community understands itself is constantly reinterpreted by how that community relates to itself, mediated by its “own” place.^{Footnote 127} It is in these registers of political theory that the Treaty of Amsterdam linked the AFSJ, as a bounded place where freedom is actualized as free movement of citizens, to Union citizens. It was only in the Lisbon Treaty, as we argue in the following section, that Union citizenship as a formal legal status was explicitly linked to the AFSJ.

II. The Lisbon Treaty: Linking AFSJ and Union Citizenship

In the Lisbon Treaty,Footnote ¹²⁸ the political aspect of the AFSJ was given further prominence. Whilst the Treaty of Amsterdam had mentioned the internal market objective before the AFSJ, and the Draft Constitution placed the AFSJ and the internal market at the same level, Article 3(2) TEU positions the AFSJ above the internal market. Unlike in the Treaty of Amsterdam, the substantive provisions on the AFSJ in Title V of the TFEU lack a reference to free movement in the internal market. These are not merely semantic differences, but reflect both the increasing significance of the AFSJ in the constitutional framework of EU law and its gradual emancipation from the economic rationale of the internal market.^{Footnote 129}

The Lisbon Treaty further elevates the political dimension of free movement in a twofold way: It proclaims that the AFSJ constitutes an area without internal frontiers^{Footnote 130} and explicitly links the area to Union citizenship.^{Footnote 131} Article 3(2) TEU states that the “Union shall offer its citizens an area of freedom, security and justice without internal frontiers, in which the free movement of persons is ensured.” The claim that the AFSJ is an area without internal frontiers does not merely constitute a Treaty objective but is further developed in the Treaty title on the AFSJ. Article 67(1) TFEU first states that the “Union shall constitute an area of freedom, security and justice” and the subsequent paragraphs programmatically relate to these three values and attach concrete legal substance to them. Article 67(2) TFEU begins the enumeration with the notion of “freedom” and states that the Union “shall ensure the absence of controls at the internal borders for persons.” In the terminology of political theory, Article 67(2) TFEU legally concretizes the abstract notion of freedom by making it a tangible reality to move within the Union unhindered by internal border controls. This is highlighted in the case law of the Court of Justice on Article 67(2) TFEU.

In Touring Tours, the Court held that Article 67(2) TFEU is not merely a programmatic provision, but also entails a primary law obligation that extends to Member States. This case concerned German legislation that imposed a general obligation on private transport companies to check the travel documents of passengers before they boarded a bus in intra-EU journeys and financial sanctions in case of non-compliance. Most of the legal reasoning in Touring Tours is concerned with the question whether the German legislation amounted to measures having the equivalent effect of border controls, prohibited by Article 23 of the Schengen Borders Code, which the Court ruled to be the case. ^{Footnote 132} However, the Court did not stop there and held that Article 67(2) TFEU also “precludes such legislation.” This finding was anything but obvious. The wording of Article 67 does not refer to the Member States, and the Court itself had decided in earlier cases that Article 67 is principally addressed to the Union.^{Footnote 133} The Court also did not need to refer to Article 67(2) TFEU to find that the German legislation violated EU law. In consequence, by anchoring an obligation on the side of the Member States —and not merely the Union— to ensure the absence of border controls directly in the substantive Treaty provisions on the AFSJ, the Court underscored the constitutional nature of the obligation to abolish border controls in the EU.^{Footnote 134}

The Court’s decision in Touring Tours illustrates a second aspect: The link between the abolition of border controls in the AFSJ and Union citizenship. Both the wording of Article 21 TFEU and Article 45 of the EU Charter of Fundamental Rights entail the right of Union citizens to “move and reside freely within the territory of Member States.” In Wijsenbeek, the Court left the question of whether the citizenship provisions in the Treaty encompass a right not to be subject to border controls unanswered. In his Opinion in Touring Tours, Advocate General Yves Bot suggested that the right of free movement includes a right not to be subject to border controls: “For citizens of the European Union, the right to move freely and unhindered within the territory of the Member States constitutes a fundamental right in accordance with Article 3(2) TEU and Article 20(2) and Article 21 TFEU.”^{Footnote 135} As the facts of the case concerned German legislation that was considered to have equivalent effects to border controls, the “right to move freely and unhindered” arguably entails a right to move across internal borders without being subject to border controls. Movement could barely be described as free and unhindered if it was subject to controls.

The Court in Touring Tours did not take up the Advocate General’s argument that the citizenship provisions in the TFEU include a right not to be subject to controls at internal borders. Rather, the Court left it open whether such a right flows directly from the citizenship provisions in the Treaties —primary law— or merely from the Schengen Borders Code —secondary law—). However, the Court’s silence on this issue should not be overstated. Already in earlier cases, the Court had stated that the right to “to enter the territory of another Member State and reside there for the purposes intended by the Treaty is a right conferred directly by the Treaty or, as the case may be, by the provisions adopted for its implementation [the Citizenship Directive].”^{Footnote 136} Thus, as the Court suggested, what the right to enter entails has to be considered in light of the provisions of the Citizenship Directive, which gives effect to the free movement rights in Articles 20 and 21 TFEU. Therefore, the right to enter another Member State in Article 5 Directive 2004/38 —Citizenship Rights Directive— is one particular aspect of the broader right of free movement in the Treaty provisions. In the past, the Court had held that Member States must not make the right of entry subject to any additional conditions that are not included in Union law.^{Footnote 137}

As the abolition of border controls essentially aims to ensure the free movement of Union citizens, as we argue above, the provisions in the Treaty and the Citizenship Rights Directive on free movement of Union citizens must be read in connection with the Schengen acquis, in particular the provisions on the abolition of controls at the internal borders.^{Footnote 138} This, however, raises the question on the exact relation between the free movement rights of Union citizenship and the rules of the Schengen Borders Code. This relation includes two different aspects.

The first aspect is a negative relation between Union citizens free movement rights and the Schengen Borders Code: The application of the provisions in the Schengen Borders Code should not impede free movement rights of Union citizens and must be in accordance with the rights in the Citizenship Directive.^{Footnote 139} The Court of Justice made clear that the Schengen Borders Code does not have the purpose “to restrict the freedom of movement of Union citizens as provided for by the FEU Treaty.”^{Footnote 140}

The second aspect is a positive relation in the sense that the rules of the Schengen Borders Code enable Union citizens to move freely in the Schengen area. As Elspeth Guild and others have argued, the provisions of the Schengen Borders Code are of “particular relevance to the practical exercise of the right of exit and entry provided for in Articles 4 and 5.”^{Footnote 141} The historical development of the Schengen acquis, as we argue above, was based on a political rationale to enhance free movement of citizens. Thus, the positive relation between the Schengen acquis and free movement rights in the citizenship provisions means that Union citizens should, in principle, not be checked at all when crossing an internal border. Article 5 of the Citizenship Directive states that “[w]ithout prejudice to the provisions on travel documents applicable to national border controls, Member States shall grant Union citizens leave to enter their territory with a valid identity card or passport . . . .“ According to Advocate General Szpunar, the fact that the current wording of this Article —“with”— has replaced “on production of” in earlier legislation, reflects the lifting of checks at the internal borders.^{Footnote 142} As such, this Article could only be validly invoked by Member States to ask a Union citizen to show their travel documents if this Member State: (i) has obtained an opt-out from the Schengen cooperation; (ii) does not yet apply the Schengen acquis in full; or (iii) has temporarily reintroduced controls at their internal borders under the Schengen Borders Code.

III. Géometrie Variable of Citizenship Rights?

If the scope of the right to free movement in the citizenship provisions in the TFEU entails a right not to be subjected to controls at internal borders, how can this be squared with the fact that some Member States—Ireland, Croatia, Bulgaria, Romania—are not yet part of the Schengen area and still have controls at their internal borders to other Member States in place? Would this not result in a geographical fragmentation of citizenship rights? Union citizens could rely on the right not to be subjected to border controls in Germany, while they would not be able to do so in Ireland.

A géographie variable of citizenship rights is the consequence of political compromises that resulted in differentiated levels of integration. Two forms of differentiated integration can be distinguished in the Treaty framework. First, the special position of Ireland and Denmark —and formerly the UK— in the Schengen framework^{Footnote 143} constitutes a form of “constitutional differentiation.”^{Footnote 144} Constitutional differentiation means that the particular legal position of these Member States is enshrined in the Treaty framework, is likely to be permanent and concerns the reluctance of these Member States to transfer critical core competences to the EU. Second, the special position of the “new” Member States —Bulgaria, Croatia, Romania, Cyprus— can be described as “instrumental differentiation.” ^{Footnote 145} Contrary to constitutional differentiation, instrumental differentiation is temporary and results from a perceived lack of factual harmonization. The Schengen Protocol clearly states that newly acceding Member States are under an obligation to participate in the Schengen rules. The upshot is that the refusal of the Council to fully apply the rules of the Schengen acquis, in particular the principle of the absence of controls at the internal borders, should continue only for as long as these Member States are considered not being able to adequately control their external borders. However, the fact that these countries have been effectively kept in Schengen purgatory based on political concerns unrelated to the management of the external border,^{Footnote 146} does raise important concerns in relation to the citizenship rights of the nationals of these countries.

Both constitutional and instrumental differentiation, however, are exceptions to the general rule of the abolition of controls at the internal borders—and therefore to the right of citizens to move freely across an internal border without being stopped and having one’s travel documents checked.