An EU Sustainable Migration: Institutional Discourse and Migration Politics

Introduction

From the migration crisis of 2015–2016 onwards, sustainable migration has become the central goal of the EU migration policy. On a first reading, the term sustainable migration carries a positive connotation and is perceived as hinting to better law and policy-making for the future of the EU. The link between sustainability and migration implies that the EU is in pursuit of a migration policy with specific characteristics. Yet it is not clear what these characteristics might be, as sustainable migration remains a concept without definition. More importantly, sustainability as a primary law objective in the EU legal order does not prima facie create legal obligations of any kind.

This raises the following question: what would a sustainable EU migration look like in terms of legal design? This article suggests that this question cannot be answered, because sustainable migration should be perceived as a political concept whose power and risk lie in its lack of definition. The link between sustainability and migration created a powerful tool at a time of broader political disagreement. In essence, the concept of sustainable migration has been used by the Commission to create the political impetus necessary to drive the EU agenda on migration forward, with little change in the legal apparatus that regulates migration as evidenced by the adoption of the Asylum and Migration Pact in April 2024.

To develop the argument, this article zooms in on sustainability and maps the appearance of the concept in the EU migration policy, as well as in EU law and policy more generally. Drawing on the work of Foucault, Anne Orford has suggested a turn to description as a mode of legal writing (Orford, 2012). Following Orford, by describing what is visible, rather than by discovering what is hidden, this article argues that sustainable migration is a political concept that has been used to unite the various political agendas on migration after 2015 and to overcome the backlog that they created for EU migration politics.

To do so, this article first provides an overview of the concept of sustainability, its relevance in EU law and policy and its disconnect from EU migration policy Section 2. Next, Section 3 maps the diverse ways in which sustainability appears in EU migration policy. The various manifestations of the actions that could fit under sustainable migration are incoherent and do not assist in drawing conclusions on the potential implications of legal design. Section 4 looks at scholarly research on sustainable migration and presents how migration studies and human geography have approached the concept of sustainable migration. It explains the value of these definitions, but also the impossibility to use them as a means to inform the EU legal framework. Finally, Section 5 draws on the work of political scientists and suggests that sustainable migration has been used as a powerful political concept at times of extreme disagreement on the future of EU migration policy. Section 6 concludes the analysis and highlights that sustainable migration has been the central promise for the future of EU migration policy since 2015. The main function of the concept was to create consensus behind an overarching goal that could unblock the reform of the EU asylum system, without however leading to any groundbreaking legal transformation.

The Disconnect of Migration from Sustainability in EU Policy and Scholarship

Sustainability is a concept that has been shaped within the UN framework, before being transposed to the EU legal framework. Specifically, sustainability became popularized in the 1970s as a central part of environmental ethics, which at that time emerged as a distinct philosophical discipline (Brennan and Lo, 2023). The emergence of the concept was linked to concerns over the finite nature of planetary resources and the danger posed by human activities to the preservation of the environment (Meadows et al., 1972). The concept of sustainability has evolved in international policy through soft law documents of different kinds and has found its most recent articulation in the 2030 Agenda for Sustainable Development (Pieraccini and Novitz, 2020). Throughout the years, numerous sectors have been linked to sustainability, and many nouns have followed the adjective ‘sustainable’, with sustainable migration being one of the most recent manifestations, first appearing under the Sustainable Development Goals.

In EU law, sustainability first made its appearance in the 1990s, and, currently, under the Lisbon Treaty, sustainable development is a primary law objective of the EU connected with economic growth, social progress, environmental protection and external action. Despite this, the evolution of the EU Sustainable Development Strategy throughout these years has taken place in complete disregard of any aspect of migration (EU Commission, 2016a, 2010, 2002, 2001). The first time the EU Sustainable Development Strategy was connected to migration was under the Von Der Leyen Commission. Arguably, this link is connected to a diffusion of sustainability-related goals across all EU policies. Specifically, Von Der Leyen's political programme aimed at integrating the 2030 Agenda in all Commission proposals, thus streamlining sustainability in EU policy (EU Commission, 2020a). In a working document issued in 2020, the Commission elaborated on the different policies adopted with the aim of implementing the Sustainable Development Goals at the EU level. In that working document, and in the Sustainable Development Goals mapping tool developed by the Commission, it appears as if all the EU policies currently pursued, and all the legal acts adopted by the EU, relate to one or more Sustainable Development Goals (SDG Policy Mapping Tool). Amongst all the different policies, the Commission mentioned the New Pact on Migration and Asylum as linked to sustainability (EU Commission, 2020a Box 1, p.6).

Despite this recent link, which in practice obfuscates the concept's meaning and implications, the EU Sustainable Development Strategy has evolved in a silo away from EU migration policy. A similar siloed approach exists in EU scholarly research on sustainability. Specifically, sustainability-related research in EU law has not hitherto engaged with the links between sustainability and migration. Rather, EU law scholars have investigated sustainability in relation to environmental law, economic law and more recently labour law. In the literature, there have been two broad ways of engagement of EU law scholars with sustainability over the last 20 years. The first is scholarship that looks at how EU law could be used as a tool to address environmental challenges with a focus on environmental and competition law (de Sadeleer, 2002; Hees, 2014; Humphreys, 2017; Kenig-Witkowska, 2017; Macrory et al., 2004; Sjåfjell and Wiesbrock, 2015; Voigt and Bugge, 2008). A second strand of scholarship developed later in time and is tied to the conceptual evolution of sustainability within the UN framework, the evolution of EU law itself after the Lisbon Treaty and the many different crises have been experienced at the EU level (economic/financial crisis, Brexit, migration crisis, public health crisis more recently), which have pointed to the inability of the existing system to achieve sustainability objectives (Tridimas, 2022). In view of the above, different scholars have argued on how different fields of EU law should be developed or applied as a means to achieve more just and sustainable societies (Alexandris Polomarkakis, 2020; Novitz, 2020). Still, any migration-related consideration is entirely absent from all the relevant works. This creates a particularly salient scholarly gap in light of the incoherent appearance of sustainable migration as a goal of the EU migration policy from 2015 onwards as will be demonstrated in the following section.

The Incoherent Appearance of Sustainability in EU Migration Policy

Migration was first linked to sustainability in the 2030 Agenda on Sustainable Development. Amongst the 17 Sustainable Development Goals and under the umbrella of reducing inequalities, Goal 10.7 targets the facilitation of ‘orderly, safe, regular and responsible migration and mobility of people, including through the implementation of planned and well-managed migration policies’ (UN General Assembly, 2015). Following the adoption of the Agenda, the UN Global Compact on Migration was adopted in December 2018 (UN General Assembly, 2018). The Compact was the first intergovernmental effort to holistically address migrant protection. Specifically, and building on already binding human rights obligations, it addressed issues of migrant protection at all stages of their journey (origin, transit and destination countries).

The EU discourse on sustainable migration predated the adoption of the Compact and developed in complete disconnect to the international policy on the matter. The analysis in this section demonstrates that there is a semantic difference between sustainable development and its relation to migration as it appears in the UN framework and sustainable migration in the way it appears in EU migration policy documents, serving to complicate the matters. Specifically, after 2015, sustainable migration has become the new buzzword describing the future of EU migration policy. In different documents issued by the Commission from 2015 to this day, sustainability appears as the central objective of EU migration policy. Nevertheless, the connection made between sustainability and migration is nowhere elaborated in a manner that can clarify any legal implications. By reviewing EU policy and legislative documents on migration from 2015 to the present, I have categorized the diverse and inconclusive ways in which sustainability appears in Table 1, based on indicative phrasing used in the relevant texts.

From Table 1, we see that sustainability appears in some EU policy documents in its literal meaning, implying the maintenance of something for the future. References to sustainability in a literal manner exist in documents regarding the implementation of the EU–Turkey agreement and referring to the ‘sustainable reduction of numbers of persons irregularly crossing the border from Turkey into the European Union as a result of Turkey's actions’ (EU Commission, 2017a, 2017b, 2017c, 2016b, 2015a). The same holds true for documents related to the Schengen area and mentioning ‘the sustainability of the substantial reduction of the migratory flow’ (EU Commission, 2016c, 2016d). These references mean that a situation of decreasing arrivals, referred to as sustainable, is capable of being maintained in the future.

Next to this literal reference to sustainability, there are references to sustainable migration as an abstract characteristic of EU migration policy. It seems to be an overarching goal for the Commission to achieve an ‘integrated, sustainable and holistic EU migration policy’ (EU Commission, 2016e, 2016f); ‘a responsible and sustainable migration policy’ (EU Commission, 2017d); an ‘efficient, responsible and sustainable migration policy’ (EU Commission, 2018a); or as the New Pact suggested ‘fair, efficient and sustainable’ EU migration policy (EU Commission, 2020b). However, it is not clear what this policy would entail in terms of legal measures.

On an equally abstract level, sustainability appears as adaptability or resilience of EU policies in the face of crisis. In different documents, there are mentions such as ‘[a] sustainable resolution of the crisis needs a step change in the Union's migration policies’ (EU Commission, 2015b) or ‘[t]he 2015 migration and refugee crisis exposed the limitations of our asylum system … it also demonstrated that a future-proof policy requires a more predictable, cooperative and sustainable approach’ (EU Commission, 2019, 2018b). The resilience of EU migration policy in the face of crisis is intimately connected to the demand of shaping an EU asylum and migration system through long-term planning and solutions as opposed to ad hoc measures (EU Commission, 2020b). Such declaratory demands for an EU sustainable migration capable of addressing future crises do not point to concrete legal measures that are premised on specific legal principles. Whilst presenting the promise of better migration management, the Commission does not provide any information on what legal principles sustainable migration should follow.

Finally, sustainable migration appears closely related to more specific actions, which will be reviewed next. These are partnerships with third countries and returns and reintegration, the creation of sustainable legal pathways and sustainable sharing of responsibility. Even if we were to accept that these actions form part of an EU sustainable migration, the analysis following shows that they come with great incoherence and create challenges for the EU legal order, which complicate them as a basis for an EU sustainable migration.

The reference to sustainable migration when it comes to partnerships with third countries does not add anything novel to the existing EU policy on the matter. Even after the adoption of the Pact, the relevant partnerships built on what was already on the table since the 2011 EU Global Approach to Migration (EU Commission, 2011). Back then, EU migration policy already articulated the need for co-operation with third countries and put emphasis on the external aspects of EU migration. In this context, the EU–Turkey agreement has been suggested as the blueprint for EU migration policy in the future (EU Commission, 2016g; see also Spijkerboer, 2018 for a critique). In parallel, returns and reintegration are presented as a central element of an EU sustainable migration. Sustainable migration is understood in this context as a means to address the root causes of migration by ensuring better living conditions for people in third countries (EU Commission, 2017e). This policy was previously connected to development co-operation and, relatedly, the sustainable development of third countries under the EU external action. It is not clear, however, what constitutes a sustainable return and reintegration policy. Nor is it clear what framework should be put in place to implement such policies with full respect to fundamental rights and the principle of non-refoulement.

Overall, partnerships with third countries and returns and reintegration reinforce the link of migration policies as part of the area of freedom, security and justice; the EU Common Foreign and Security Policy; and development co-operation. As a result, the instruments used to pursue such policies come with significant challenges for the EU constitutional structure, which have already been explored in literature (Carrera, 2019; Santos Vara, 2019). In brief, such practices raise issues with respect to the horizontal division of competences, the division of powers between the EU and the Member States and the limitation of judicial review by the Court of Justice of the EU (Articles 40 TEU and 275 TFEU, Andrade, 2018; De Capitani, 2020; Matera, 2019). This has been exemplified in the legal issues raised by the EU–Turkey deal and that continue to be raised in the informal co-operation pursued by the EU with various third countries (Vara et al., 2023). Scholars have demonstrated in great length the human rights issues raised by the growing informalization of EU action in the external aspects of migration (Frasca and Roman, 2023; Moreno-Lax, 2022; Slominski and Trauner, 2021). Cardwell and Dickinson have coined the term ‘formal informality’ to describe the governance framework guiding EU migration policy on the matter (Cardwell and Dickson, 2023). By this, they refer to the proliferation of instruments that resemble formal tools of EU action whilst lacking procedural safeguards. Such instruments can by no means inform a sustainable EU migration without endangering core principles of the EU constitutional architecture (such as rule of law, democratic accountability and access to justice).

In addition to this, there is a demand for sustainable legal pathways both for people in need of protection and for attracting talent to the EU (EU Commission, 2020b). Two rationales currently underpin sustainable legal pathways: preventing deaths at sea and connecting migration to the EU economic growth. In the first, safe legal pathways are presented as a means to tackle unsafe and irregular routes, which create more deaths at sea (EU Commission, 2020b). On this matter, a recommendation was made by the Commission in 2020 on continuing the resettlement schemes in place, whilst the Regulation Establishing a Union Resettlement and Humanitarian Admission Framework will soon be adopted (EU Commission, 2016f, 2020c, 2023a). Contrary to what might be imagined, the proposed Regulation harmonizes the procedure that should apply to resettlement and humanitarian admission but does not create any obligation for Member States to create such pathways (Recital 19 of the proposed Regulation; Recital 19, Article 1(2) and (2a) Amended Proposal). Overall, it is unclear how the Commission envisions tackling unsafe routes and preventing deaths at sea, whilst continuing to adopt policies that promote Member State discretion and undermine human rights (Boer and Zieck, 2020; Loxa, 2023). The lack of innovative proposals should not come as a surprise if we also consider the CJEU and ECtHR case law on humanitarian visas, both of which found no obligation of creating a humanitarian corridor to EU Member States, stemming from either EU law or human rights (C-638/16 PPU, X and X, 2017; MN and others v Belgium, app No. 3599/ 18, 2020).

In parallel with protection-related pathways, labour-related pathways link migration to the economic needs of the EU. In the relevant references, various actions, especially those targeting highly skilled workers, are mentioned as a means to ensure growth and address the long-term economic and demographic challenges faced by the EU (Recital 3, Directive 2009/50/EC; EU Commission, 2018c, 2016h, 2015). In these mentions, it is the EU welfare and economic system that is to be sustainable, thanks to specific labour needs covered by migrants (EU Commission, 2020b, 2016i). After the adoption of the recast Blue Card Directive in 2021, the Commission issued a communication where different measures were suggested as a means to achieve the objective of an EU sustainable migration policy (EU Commission, 2022a). On the legislative side, the Commission referred to the revision of the Long-Term Residents Directive and the Single Permit Directive in order to enhance the rights and mobility of third-country nationals in the EU (EU Commission, 2022a, 2022b, 2022c). At the same time, talent partnerships to attract workers from specific third countries; a European Youth Mobility scheme that could create rights to reside, travel and work for a limited time in the EU; a framework to facilitate access to innovative entrepreneurs; and the possibility of harmonizing admission for care workers were also discussed (EU Commission, 2022a).

Finally, there are also references to ‘sustainable and fair distribution of applications’ or ‘sustainable sharing of responsibility’ (EU Commission, 2016j, 2016k, 2016l). Behind such references lies the idea that the Dublin system is unsustainable and that EU asylum policy should be revisited to ensure its functioning for the future. And yet references to sustainable sharing of responsibility under the Pact, and the attempt to shape EU asylum law accordingly, have not delivered results. The agreement reached at the Council on the proposed Regulation on Asylum and Migration management did not change the responsibility rules under Dublin, whereas a flexible solidarity mechanism was put in place as a means to ensure sustainable migration (Council of the European Union, 2023; European Council on Refugees and Exiles, 2023). This appears problematic. The principle of solidarity has been subject to much scrutiny in relation to its normative status and the constant attempt of Member States to circumscribe it (C-643/15 and C-647/15, Slovakia v Council and Hungary v Council, 2017; Groussot and Karageorgiou, 2023; Karageorgiou, 2018). Despite the increasing positioning of solidarity at the centre of the EU legal order, the concept remains elusive, but at the same time, it is connected to an underlying idea of shared identities that motivate common objectives and obligations between groups (Küçük, 2023). Sustainable migration is also elusive. Even if we were to turn to the UN framework for guidance (which as we shall see in the next section is not of assistance), a central demand would be a balancing of interests of host states, states of origins and the migrants themselves, which extends beyond bounded communities with shared identities. In that sense, mixing sustainability with sharing of responsibility through solidarity owed by the Member States could go one of two ways. A first would be that sustainability would conceptually open up solidarity beyond bounded communities, which would be highly implausible in light of the long intellectual history of solidarity and the difficulty of devising a universal type of solidarity (Moreno-Lax, 2017). The other way is that the elements of balancing inherent of sustainability would be introduced in solidarity, further undermining the principle (Loxa and Stoyanova, 2022).

Overall, the goal of sustainable migration appears at both an abstract level and a specific level. It is tied to many EU migration law areas that have different objectives and are based on different rationales. Specifically, sustainability with regard to the development of third countries refers to policies that develop across different areas of EU law, which come with different levels of fundamental rights guarantees. The references add nothing to the existing policies and reinforce the model of outsourcing migration control and evading responsibility for asylum seekers, as the relevant actions continue to develop through informal channels of co-operation, which evade democratic and judicial scrutiny (den Heijer et al., 2016). Moreover, safe legal pathways are presented as a means to ensure the protection of asylum seekers, who should not be forced to embark on perilous journeys. But when it comes to binding measures that create rights for migrants, legal instruments related to labour migration are prioritized. This is not a negative evolution, as labour-related pathways are indeed necessary for the development of the EU economy (EU Commission, 2022a). Rather, the point of tension is the following. Sustainable legal pathways are framed as a way to reinforce the role of the EU as a promoter of human rights, but in practice, the framework does not fundamentally transform pathways for people in need of international protection. Hence, it is impossible to conclude on what legal design sustainable migration demands. Finally, sustainable sharing of responsibility serves to further blur the principle of solidarity under Article 80 TFEU and does not seem to have any concrete legal implication. All these inconsistencies and the divergent objectives of EU migration policy, which are all set under the umbrella of sustainable migration, necessitate the closer examination of this concept. The next section engages more closely with literature on the concept of sustainable migration and examines whether scholarly analysis can provide insight into the potential implications of this concept.

Attempts to Define Sustainable Migration

The link between sustainability and migration that was made in Sustainable Development Goals and the 2018 Global Compact has resulted in literature focused on the nature of the compact as a soft law instrument and its interaction with international human rights law (Desmond, 2020; Guild and Wieland, 2020; Hilpold, 2020). Despite the references to sustainable migration in EU and international policy as Section 3 showed, scholarship has not engaged in research on the legal implications of this objective. Some authors have used the term ‘sustainable migration’ in a declaratory manner, as a demand for a type of migration policies, without any clear definition of what these should entail (Klein Solomon and Sheldon, 2019).

Outside legal scholarship, migration studies have been investigating the relation between development and migration for a long time (Faist et al., 2011). From the 1960s to this day, migration has been connected to development by outlining how the flow of people and, consequently, of money (through remittances) as well as of knowledge (acquired in the host country and employed in the country of origin upon return) can impact the development of host countries and countries of origin of migrants (Faist and Fauser, 2011).

In this regard, it should not come as a surprise that research into potential definitions of the term ‘sustainable migration’ has been explored outside the field of legal science and with an emphasis on development considerations (Al-Husban and Adams, 2016; Janker and Thieme, 2021; Picard and Worrall, 2011). Specifically, the Peace Research Institute of Oslo produced two papers, which offered definitions of sustainable migration from the perspective of migration studies and human geography. In these papers, it was acknowledged that the concept of sustainable migration, especially without an established definition, is a powerful one, in the sense that its rhetorical effects can be seen as fitting both liberal and restrictive migration agendas (Carling and Bivand Erdal, 2018; for similar arguments on environmental justice see Dryzek, 2012; Voigt, 2005).

The first definition, proposed by Bivand Erdal et al., suggested that sustainable migration is ‘migration that ensures a well-balanced distribution of costs and benefits for the individuals, societies and states affected, today and in the future’ (Bivand Erdal et al., 2018). The second definition, proposed by Betts and Collier, took a different stance, suggesting that sustainable migration is ‘migration that has the democratic support of the receiving society, meets the long-term interests of the receiving, sending society, and migrants themselves, and fulfils basic ethical obligations’ (Betts and Collier, 2018). These definitions offer a starting point for conceptualizing sustainable migration policies, but they cannot provide much guidance as to the legal implications of the concept. Apart from the fact that the distribution of costs and benefits and the evaluation of long-term interests of different societies cannot be easily translated into law, these definitions encounter another obstacle, namely, the position of individuals and their agency as rights-bearers in law.

On this matter, Guild has highlighted the risk that arises from linking sustainable development and migration, by reviewing the link of the Global Compact on Migration to the 2030 Sustainable Development Agenda (Guild, 2020) The risk arises due to the fact that ‘the economic objectives of development that are not framed in legal terms are extended to migration, framing migration as a development tool’ (Guild, 2020, p. 248). However, migration involves individuals who have human rights protected under international law, and balancing their rights against state interests risks further diminishing migrants' protection (Guild, 2020, p. 248). In the same article, Guild also examines how policies linking migration to development (i.e., addressing brain drain, remittances and circular migration) could potentially lead to conflict with human rights, suggesting that the Global Compact on Migration should be applied within the framework of human rights standards rather than Sustainable Development Goals (Guild, 2020, p. 249).

Similarly, the EU legal system is centred on individual agency, and human dignity is at the core of this legal order under Article 2 TEU and the Charter of Fundamental Rights. The caveats regarding migrants' rights relate more to the (intended or unintended) creation of spaces of liminal legality, which exclude migrants' legal protection, rather than to the provisions of the EU legal framework. In such a context, viewing migrants as transactional tokens whose value is measured by their capital contribution to the country of origin and the country of destination could hardly inform the legal implementation of an EU sustainable migration, in that such a view would conflict with the centrality of human dignity in its legal order.

The above analysis highlights the difficulty of identifying elements that can inform a legal framework structured around the objective of sustainable migration. More importantly, it shows that the fuzziness of sustainability allows for different types of migration policies and for different underlying notions of human rights protection: from utmost respect for all to cost–benefit analysis of human lives under the pretext of realism. It is precisely the flexibility of sustainable migration and the lack of concrete legal demands from sustainability that can frame the concept as a political one with a very specific function in EU migration politics in the period following the migration crisis of 2015.

Sustainable Migration as a Political Concept

Given the difficulties in defining sustainable migration and the divergent goals that can be pursued under the pretext of sustainability, the following question arises: how should we understand the overarching objective of shaping a sustainable EU migration policy as presented by the Commission? Before suggesting an answer, it is worth reflecting on the time when sustainable migration became the core objective of EU migration policy. Despite the long existence of sustainability in the EU legal order and in the international scene, the promise of sustainable migration came to the fore in a period characterized by intense political disagreements at national and EU levels as to how the EU should approach the area of migration. Specifically, a link between sustainability and migration in EU migration policy appears for the first time after 2015 and the collapse of the Common European Asylum System in 2015 (cf. Thym, 2016). And whilst various concepts have at times appeared in EU migration policy without a specified legal meaning, none has been set as the new overarching goal framing the future of EU action in the field in the way sustainable migration does (Jesse, 2016 on integration).

At this stage, it is also important to note that amongst the various actors implicated in EU law making, the Commission has been the central one using the discourse of sustainable migration. This should not come as a surprise as the Commission has historically used its monopoly of initiative ‘skilfully’ as put by Thym, to present itself as a source of expertise in the area of migration (Thym, 2022, p. 60). In contrast, the Council operates under a veil of secrecy, making it almost impossible to access the discussions that preceded the negotiation of different instruments and to thereby closely examine the various positions of the Member States therein and the way in which they did or did not use sustainable migration (Thym, 2022, p. 63). In light of this and the analysis above, I suggest that sustainable migration has been used inconclusively by the Commission and without any attempts at definition during particularly challenging times for EU migration policy, to draw support from many and opposing sides. The term has allowed for flexibility as to what kind of migration policies can be associated with this overarching objective.

Sustainable migration should, thus, be understood as a political concept whose power and risk lie precisely in the lack of any legal implications. Understanding sustainable migration as a political concept can inform our perception of the many references of sustainability in EU migration policy; it can explain the appearance of the concept after the 2015 migration crisis, as well as the adoption of the Pact in April 2024, which shows no fundamental change in the legal principles underlying EU migration (Peers, 2023). At the same time, this situates sustainable migration, as expressed in the EU migration policy, in a longer theoretical tradition that views sustainability and sustainable development as concepts located in political discourse with contested and potentially antithetical meanings (see Baker, 2007; Jacobs, 1999 on the EU Sustainable Development strategy). The framing of sustainable migration in this way perfectly captures the diversity and incoherence of the various manifestations of sustainable migration as demonstrated in Section 3. The different approaches to sustainability in EU migration policy since 2015 should not create confusion. There is no unitary meaning of sustainable migration, which creates demands of a particular legal design and which is obfuscated in EU migration policy. Rather, sustainable migration has been ‘a powerful tool for political consensus’ at a time when an intense lack of consensus was threatening the future of the EU project in many respects (Baker et al., 1997, p. 69).

Conclusion

This article critically investigated the appearance of sustainable migration as the overarching goal of EU migration policy after 2015. The analysis engaged with EU law, policy and scholarship on sustainable development and demonstrated the complete absence of migration from the relevant area. Subsequently, it mapped the diverse ways in which sustainability has appeared in EU migration policy documents. The analysis demonstrated that there is a semantic difference between sustainable development and its relation to migration as it appears in the UN framework and sustainable migration in the way it appears in EU migration policy documents. Rather, after the migration crisis, sustainable migration has become a central buzzword of EU policy. The term operates both as an abstract goal of EU migration policy and as connected to more specific actions. However, there is no clarity or coherence as to the legal implications that such a goal might have.

Looking at scholarly research on sustainable migration and drawing on the work of political scientists on sustainability, this article argues that sustainable migration should be understood as a political concept whose central function has been to unite Member States and overcome the blockage created in the attempt to reform the EU asylum system after the 2015 migration crisis, without however bringing a fundamental change. Looking into sustainable migration through the lens of political science and the similar approach to sustainable development allows us to understand its power and risk. By analogy to Baker's suggestion on sustainable development, the commitment to sustainable migration has been key for the creation of consensus over the future of EU migration, and at the same time, it has allowed a great flexibility as to what such future might look like (Baker et al., 1997, p. 28).

It is important to reflect on how the concept of sustainable migration has become central since 2015. The collapse of the Common European Asylum System and its failed reform, the practical collapse of Schengen, the heated debates on migration at EU and national levels and the growing support for restrictive migration policies frame the setting in which sustainable migration was put forward as the central promise of future law and policy-making. Eventually, after years of negotiations that perpetuated a sense of crisis in EU migration politics, the recent agreement reached on the Pact was presented as historic (EU Commission, 2023b; Zaun and Ripoll Servent, 2023). Understanding the past references to sustainable migration in light of it being a political concept captures the advantages of shaping a political compromise, whilst presenting the promise of future amelioration. In practice, however, this symbolical commitment of the EU to sustainable migration throughout these years did not signal any transformation from past policies but rather only a necessary political consensus for further limitation of migrants' rights (cf. Reslow, 2019; Sunderland, 2023).