Migration as Leverage: Morocco’s Strategic Use of Migration in the Western Sahara Dispute

By Maya Ikene

Promoted by Prof. Dr. Hendrik Vos

[September 2025]

This paper analyses how Morocco leverages migration in its relations with the European Union to advance its claim over the Western Sahara. Using process tracing of the 2021 Ceuta crisis, supported by (EU) policy documents and media sources, the study applies three frameworks: asymmetric dependence, coercive diplomacy, and coercive engineered migration. Findings show that Morocco’s temporary relaxation of border controls enabled it to extract political concessions, exploiting EU divisions and sensitivities to migration. The paper highlights how transit states exercise agency in migration diplomacy, while exposing tensions between EU pragmatism and its normative commitments.

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Introduction

Migration has become a central instrument in international politics, particularly along the borders of the European Union. As the EU continues to externalise its migration management through deals with neighbouring transit states, questions arise about how these arrangements affect foreign policy, human rights, and geopolitical (in)stability. Situated on vital migration routes between the European and African continents and sharing strong economic and diplomatic ties with the EU, Morocco is a key partner in this strategy. The Kingdom occupies a crucial position in controlling irregular migration flows into Europe. At the same time, Morocco has an unresolved territorial dispute over the Western Sahara, a former Spanish colony it largely annexed in 1975. While the international community remains strongly divided regarding this matter, Morocco has increasingly sought diplomatic recognition of its sovereignty over the Western Sahara region, often through indirect pressure. This pressure has included the strategic manipulation of migration cooperation, raising critical questions about the instrumentalisation of human mobility for geopolitical gain. This study contributes to a growing body of research on migration diplomacy and the geopolitical agency of transit states. Previous scholars have highlighted the asymmetry of migration partnerships (Greenhill 2010; Keohane & Nye 2013), the securitisation of border policies (Geddes 2014; Moreno-Lax 2020), and the EU’s normative dilemmas when engaging with authoritarian regimes (Zardo & Loschi 2020). However, the extent to which countries like Morocco can exploit migration cooperation to gain ground on unrelated political issues, such as territorial recognition of the Western Sahara, remains underexplored.

This paper focuses on the Ceuta crisis of May 2021, when over 8,000 migrants entered the Spanish enclave after Moroccan border forces relaxed their controls. This happened shortly after Spain allowed Brahim Ghali, the leader of the Polisario Front (the pro-independence movement in Western Sahara), to receive medical treatment. The timing of the border incident raised suspicions that Morocco had orchestrated or at least tolerated the migratory pressure as a form of retaliation and a negotiation tool. The study applies process tracing to examine this empirical case, guided by three theoretical frameworks: Firstly, asymmetric dependence, to assess the unequal but interdependent nature of Morocco–EU relations. Secondly, coercive diplomacy, to analyse the use of pressure and threats in foreign policy. Lastly, coercive engineered migration: to understand how states may deliberately manipulate migratory flows to extract concessions. These three frameworks are tested against policy responses from the EU and its member states, official communications, and the diplomatic timeline surrounding the crisis. The paper finds strong evidence that Morocco uses migration not only as a tool for border control but as a deliberate strategy of leverage in international negotiations, particularly regarding Western Sahara. In doing so, the study exposes a significant vulnerability in the EU’s external migration policy: its reliance on third countries with divergent political goals creates room for instrumentalisation. It also raises ethical and strategic concerns for the EU, whose image as a defender of international law and human rights is increasingly at odds with its pragmatic partnerships. The research aims to shed light on the geopolitical consequences of migration externalisation and to encourage more coherent and principled approaches in EU foreign policy, especially in contexts marked by unresolved conflicts and asymmetric power relations.

Materials and methods

The study adopts a qualitative research design, guided by a theory-testing case study approach. The aim is to investigate the extent to which Morocco strategically leverages its role in EU migration policy to secure political support for its claim over the Western Sahara. To unpack the causal relationship between migration cooperation and geopolitical recognition, the research relies on process tracing as its core method. This technique is particularly suited to theory-testing research and allows for the detailed reconstruction of causal mechanisms within a single, bounded case. It enables the researcher to evaluate whether observed sequences of events are consistent with theoretical expectations and whether alternative explanations can be ruled out. Process tracing is thus especially valuable in the context of foreign policy analysis, where political actions are multi-layered, indirect, and often strategically ambiguous.

The analysis is structured around three interrelated theoretical perspectives, each operationalised into a testable hypothesis:

1. Asymmetric Dependence (Keohane & Nye, 2013): This framework posits that states embedded in asymmetric interdependence can still exert influence over more powerful actors by leveraging strategic assets.

Hypothesis 1: If asymmetric dependence is at play, Morocco will be shown to strategically use its role as a key transit country to pressure the EU in unrelated policy domains, such as territorial recognition of Western Sahara.

2. Coercive Diplomacy (George & Simons, 1994; Jakobsen, 2016; Schelling, 1966): This theory explores how limited threats, and pressure can be used to alter an adversary’s behaviour. It includes mechanisms such as the credible threat of costs, deadlines, and conditional incentives.

Hypothesis 2: If coercive diplomacy is involved, there will be evidence that Morocco applied diplomatic or operational pressure, e.g., relaxing border controls, intended to punish or coerce the EU or a specific member state into compliance on the Western Sahara issue.

3. Coercive Engineered Migration (CEM) (Greenhill, 2010): This concept theorises the deliberate manipulation or exploitation of migratory flows as a tool of statecraft. Migrants are instrumentalised as vectors of pressure, often aimed at destabilising or extracting concessions from target states.

Hypothesis 3: If CEM is present, Morocco will have deliberately manipulated or tolerated irregular migration flows to create political and logistical pressure on the EU, capitalising on its internal divisions and humanitarian sensitivities.

Each hypothesis was translated into a causal chain with associated indicators and threshold conditions. These mechanisms were tested against a diverse set of qualitative data sources. These included official documents and press releases from the European Union and its member states, public statements by Moroccan, Spanish and EU officials, parliamentary debates, United Nations reports (especially from the MINURSO mission), and reputable media coverage, notably from El País, Le Monde and France24. Triangulation across source types ensured consistency and credibility, while also allowing for the identification of discursive patterns and potential contradictions.

The analytical procedure combined deductive theory testing with inductive evaluation of empirical coherence. For each hypothesis, the study assessed whether the evidence met three core criteria: temporal sequencing (whether events unfolded in the expected order), explanatory coherence (whether the mechanism provided a plausible account), and congruence with theoretical expectations. The study also examined competing explanations, including administrative failures, spontaneous migration surges, and humanitarian factors, to assess the relative strength of the proposed causal mechanisms. Particular attention was paid to identifying strong process-tracing tests, such as “hoop tests” or “smoking gun” evidence, hat might confirm or falsify specific claims.

While the single-case design limits the generalisability of findings, it allows for a detailed, context-sensitive investigation of a complex geopolitical interaction. The possibility of equifinality, where multiple mechanisms may be simultaneously at work, was acknowledged, and the study refrains from asserting monocausal conclusions. Instead, it evaluates the plausibility and explanatory power of each hypothesis within the specific temporal and diplomatic context of the Ceuta crisis. Ultimately, this methodological approach provides a structured framework for examining how transit states such as Morocco may leverage migration governance for strategic purposes, and it highlights important vulnerabilities in the EU’s externalisation approach, particularly in contexts marked by unresolved conflicts and asymmetric interdependence.

Results

1. Asymmetric Dependence and strategic leverage

The analysis of the 2021 Ceuta crisis reveals strong support for the theoretical framework of asymmetric dependence, as formulated by Keohane and Nye (2013). Although the EU enjoys superior structural power, economically, diplomatically, and institutionally, it has developed a form of functional dependence on Morocco in the field of migration management. This interdependence is asymmetrical: while Morocco benefits from European aid, trade, and diplomatic ties, it is the EU, and especially frontline member states like Spain, that face acute political vulnerability when Morocco withholds its cooperation.

This dynamic was evident during the 2021 Ceuta crisis. By temporarily relaxing its border enforcement and allowing thousands of migrants to cross into Spanish territory, Morocco demonstrated that it could produce high-impact political consequences for Spain at relatively low cost to itself. This action exemplifies what Keohane and Nye describe as the strategic use of asymmetry: a weaker actor exploits the vulnerabilities of a stronger one in a key policy domain. In this case, migration.

These findings directly support Hypothesis 1, which posited that Morocco strategically leverages its asymmetric role as a migration buffer to exert pressure on the EU regarding the Western Sahara. The case confirms the core assumption that functional interdependence, when unevenly distributed, can be transformed into effective geopolitical leverage. Morocco’s geographic position and its control over migratory flows became key strategic assets in advancing its territorial claims, thereby validating the relevance and explanatory power of the asymmetric dependence framework in this context.

2. Coercive Diplomacy and Morocco’s pressure tactics

The Ceuta case also provides empirical evidence for the theory of coercive diplomacy, initially developed by Thomas Schelling (1966) and later refined by George and Simons (1994) and Jakobsen (2016). This framework explains how states use limited, controlled forms of pressure, such as threats or temporary disruptions. The aim is to compel adversaries or partners to make political concessions without escalating into full-blown conflict.

Morocco’s actions in May 2021 closely follow this model. The temporary suspension of border enforcement, which enabled more than 8,000 migrants to cross into the Spanish enclave of Ceuta, was not officially accompanied by any public ultimatum or declaration. Yet, in diplomatic terms, the timing was far from coincidental. The event occurred immediately after Spain admitted Brahim Ghali, leader of the Polisario Front, for medical treatment, an act perceived by Morocco as a provocation and a betrayal of its core national interest regarding the Western Sahara. The absence of formal statements served a strategic function: it allowed Morocco to exert pressure while maintaining plausible deniability, thereby reducing the diplomatic costs associated with overt coercion.

When Jakobsen’s (2016) four success conditions for coercive diplomacy are applied to the Ceuta case, a high degree of congruence emerges:

Credible threat: The sudden influx of migrants into Spanish territory constituted an immediate and visible crisis. It created logistical challenges and intense political pressure within Spain, particularly for the Sánchez government, which faced fierce domestic criticism and media scrutiny. The threat was not merely hypothetical; Morocco demonstrated its capacity and willingness to inflict real costs by weaponising its control over border flows.
Time-bound urgency: The crisis was temporally contained. Within days of the escalation, and shortly after Ghali departed from Spanish territory, border cooperation was restored, and diplomatic channels were reopened. This brevity underscores the tactical nature of the manoeuvre: it was not meant to ignite a prolonged standoff, but to create a short, sharp disruption that would signal discontent and provoke reconsideration.
Guarantee of non-repetition: Once bilateral negotiations resumed and diplomatic tensions began to de-escalate, no further migration incidents of comparable magnitude occurred. This restraint suggested that Morocco’s objective was narrowly defined and conditionally limited to signal the cost of political gestures that contradict Moroccan sovereignty claims, not to undermine the bilateral relationship altogether.
Inducement or reward: The clearest sign of successful coercive diplomacy came in March 2022, when Spain made a dramatic policy reversal by publicly endorsing Morocco’s autonomy plan for Western Sahara, abandoning its previous stance of neutrality. While this shift was not formally linked to the Ceuta incident, the temporal proximity and diplomatic context strongly suggest a causal relationship. From Morocco’s perspective, the episode had served its purpose: pressure had translated into political concession.

Taken together, these elements provide strong evidence that Morocco pursued a deliberate strategy of coercive diplomacy aimed at influencing Spain’s position on a long-standing territorial dispute. The use of migration as a non-military lever fits well within the model outlined by Jakobsen, who emphasises the effectiveness of calibrated pressure when paired with limited, achievable goals and clear off-ramps for de-escalation.

Moreover, Morocco’s strategy exemplifies the growing use of hybrid diplomatic tactics by middle powers: combining indirect coercion with diplomatic ambiguity to shape the behaviour of stronger partners. In this context, the Ceuta crisis should not be seen as an isolated border incident but as a calibrated act of statecraft, one that leveraged controlled disruption to achieve a geopolitical objective. It highlights how coercive diplomacy, far from being limited to military crises, can operate effectively in domains such as migration governance, especially where structural asymmetries are softened by functional interdependence.

These findings directly support Hypothesis 2, which posited that if coercive diplomacy were at play, Morocco would deploy limited but targeted pressure, such as the suspension of migration cooperation, to extract political concessions in the Western Sahara dispute. Furthermore, Jakobsen’s four success conditions were expected to be observable in the empirical record. The Ceuta case meets all four criteria: a credible threat was enacted, the crisis was time-bound, it ceased after the initial message was conveyed, and a clear policy shift followed. Taken together, these elements confirm that Morocco’s strategy was not reactive or incidental, but rather a calculated application of coercive diplomacy.

3. Coercive Engineered Migration as an opportunistic strategy

Finally, the Ceuta crisis also aligns closely with Kelly Greenhill’s (2010) theory of coercive engineered migration (CEM), which conceptualises cross-border migration not merely as a humanitarian or economic phenomenon, but as a strategic tool deliberately manipulated by states to achieve specific political, military, or economic objectives. In this framework, migration flows become instruments of coercion, designed to impose pressure on target states and extract concessions by exploiting their institutional and societal vulnerabilities.

Morocco’s actions during the Ceuta incident conform particularly well to what Greenhill (2010) terms the “opportunist” subtype of coercive engineered migration. In contrast to cases where states manufacture migration flows entirely from scratch, opportunistic senders exploit pre-existing pressures, such as economic hardship, youth unemployment, or regional instability, and simply remove barriers that would normally prevent these pressures from materialising into large-scale movement. In the Moroccan context, this involved withdrawing or relaxing routine border enforcement, particularly in regions with already high emigration potential, such as Northern Morocco. Rather than actively forcing people across the border, the state enabled latent migratory energy to erupt at a politically sensitive moment, thus generating a visible and disruptive incident at minimal direct cost.

Two of the core coercive mechanisms outlined by Greenhill are observable in the Ceuta case. First, the exhaustion of institutional capacity: the arrival of over 8,000 migrants within a short timeframe overwhelmed the logistical, humanitarian, and administrative infrastructure in Ceuta. Local and national authorities were caught off guard, triggering a rapid deployment of additional Spanish security forces and a series of emergency political meetings.
Second, the stimulation of internal political unrest: the crisis ignited intense debate within Spanish domestic politics. The government of Pedro Sánchez faced harsh criticism from both the political opposition and segments of the public. Migration, already a contentious topic in Spain, became a lightning rod for broader frustration, putting pressure on the government’s handling of foreign policy, its relationship with Morocco, and its stance on Western Sahara.

Furthermore, the Ceuta episode reinforces Greenhill’s claim that CEM is particularly effective when targeted at liberal democracies. These regimes, characterised by pluralistic media environments, electoral accountability, and human rights obligations, are especially vulnerable to the domestic fallout of migration-related crises. Public opinion, civil society mobilisation, and media framing can quickly transform border disruptions into political liabilities. Morocco’s strategy appears to have capitalised on this dynamic by carefully timing the border relaxation to coincide with the peak of a diplomatic dispute. Namely, the controversy surrounding Spain’s decision to host Brahim Ghali. In doing so, Morocco increased the reputational and political cost of defiance, while avoiding confrontation or overt demands.

Importantly, the Ceuta crisis also illustrates the deliberate ambiguity often associated with CEM. Unlike traditional coercive diplomacy, which tends to involve explicit threats or demands, coercive engineered migration relies on a subtler form of signalling. The coercive state sends a message not through formal communication, but through the disruptive consequences of its inaction. The burden falls on the target state to infer the motive, recognise the strategic intent behind the disruption, and respond accordingly. In the Ceuta case, no public ultimatum was issued by Rabat. Yet the sequencing and context left little room for misinterpretation: Spain’s perceived affront to Moroccan interests was met with immediate and tangible disruption, and cooperation resumed once the diplomatic dispute began to cool. This form of calibrated ambiguity gave Morocco plausible deniability while still delivering a clear message to Spanish and EU policymakers.

These findings offer strong support for Hypothesis 3, which posited that Morocco would deploy a strategy of coercive engineered migration by manipulating existing migration dynamics to extract political concessions, particularly in the context of the Western Sahara dispute. The Ceuta incident provides compelling evidence of this mechanism: a pre-existing population of potential migrants was leveraged at a politically opportune moment, resulting in significant pressure on a democratic target state. Moreover, the absence of direct threats, the use of ambiguity, and the reliance on indirect disruption rather than overt force are all consistent with Greenhill’s model.

In sum, the Ceuta crisis demonstrates how migration can function as a strategic vector of coercion, particularly in asymmetrical geopolitical relationships involving democratic target states and strategically significant transit countries. Morocco’s use of CEM did not require the creation of new migratory drivers or the deployment of a large-scale force. Instead, it relied on the selective withdrawal of state control, the political salience of migration in the EU, and the institutional vulnerabilities of democratic governance. As such, the episode underscores the evolving nature of coercive statecraft in the 21st century, where borders, people, and mobility become tools in the pursuit of geopolitical goals.

Discussion

The 2021 Ceuta crisis offers a revealing case of how migration can be used not merely as a border management issue but as a multidimensional instrument of foreign policy and geopolitical negotiation. This study has shown that Morocco’s approach was not ad hoc or reactive but embedded in a broader repertoire of strategies through which transit states exploit their positional power vis-à-vis the European Union.

Rather than relying on confrontation, Morocco adopted an approach that blurred the line between cooperation and coercion, leveraging its control over migration flows as both a bargaining chip and a political signal. This dynamic reflects a wider transformation like migration diplomacy: transit states are no longer just recipients of EU policy, but increasingly active agents capable of shaping outcomes in ways that serve their strategic priorities. In this sense, the Ceuta crisis is not an outlier, but part of an emerging pattern where structurally weaker states engage in calculated acts of leverage through functional interdependence.

The case also brings into focus the complex interplay between asymmetry, ambiguity, and agency. Morocco’s use of migration as a foreign policy tool did not require direct threats or military capacity. Instead, it relied on three interwoven mechanisms: exploiting the EU’s operational dependence on its cooperation (asymmetric leverage), applying non-violent but high-impact disruption (coercive diplomacy), and manipulating migratory flows in a way that avoided formal accountability (coercive engineered migration). Together, these strategies point to a more hybrid and adaptive form of coercion, one that thrives in policy areas marked by institutional fragmentation, public sensitivity, and normative inconsistency.

From a European perspective, the findings raise difficult questions about the sustainability and ethics of migration externalisation. Delegating border control to third states may yield short-term control over irregular migration, but it also creates long-term vulnerabilities, especially when partners pursue goals that clash with EU values or legal commitments. The Moroccan case illustrates how this dependency can be exploited not only to delay or disrupt cooperation but to pressure the EU and its member states into adjusting their stance on unrelated geopolitical matters, such as territorial disputes.

At a broader level, the study contributes to rethinking how power operates in asymmetrical relationships. Rather than treating coercion as a domain reserved for dominant states, the findings suggest that middle and even weaker powers can successfully instrumentalise non-military assets, such as migratory pressure, to shape international negotiations. This insight has implications beyond the Mediterranean: in an increasingly multipolar world, tools like migration, energy transit, and digital infrastructure are becoming integral to the repertoire of strategic influence.

Ultimately, the Ceuta case should serve as a cautionary tale for the EU. If migration governance continues to be outsourced without clear accountability, normative safeguards, or mutual transparency, the Union risks entangling itself in transactional relationships that undermine both its strategic autonomy and its credibility as a values-based actor. Future policy must therefore be more attuned to the geopolitical agency of partner states and more resilient to the consequences when that agency is used for coercive ends.

Conclusion

This study has demonstrated that Morocco strategically leveraged its role in EU migration management to advance its geopolitical objective of gaining international recognition for its claim over Western Sahara. Using the 2021 Ceuta crisis as a case study, the research applied three interrelated theoretical frameworks, asymmetric dependence, coercive diplomacy, and coercive engineered migration, to uncover how migration policy can be instrumentalised for foreign policy gains. The findings confirm that Morocco exploited the EU’s functional dependence on its border control cooperation to exert targeted pressure on Spain and the EU in its whole at a critical diplomatic moment. By temporarily relaxing border enforcement and generating a high-profile migratory episode, Morocco signalled dissatisfaction with Spain’s actions regarding the Polisario Front and extracted a diplomatic concession shortly thereafter.

Beyond the empirical case, the findings carry broader implications for the study of power and agency in international relations. They reveal how a state commonly perceived as the weaker partner in an asymmetrical relationship can nonetheless exercise considerable leverage by exploiting functional interdependence. Migration governance, often framed as a technical or humanitarian issue, emerges instead as a domain of strategic competition, where border control can be transformed into a bargaining chip. This underscores that coercive power in world politics is not the exclusive preserve of great powers; middle states and even weaker actors can effectively deploy non-military instruments such as mobility to shape outcomes in their favour.

For the European Union, the Moroccan case exposes a structural vulnerability at the heart of its external migration policy. By outsourcing migration control to neighbouring states, the EU gains short-term stability but incurs long-term dependence. This dependence allows partners with divergent political agendas to instrumentalise cooperation, undermining both the EU’s strategic autonomy and its credibility as a normative power committed to international law and human rights. The Ceuta incident illustrates this tension vividly: an organisation that prides itself on principled foreign policy was forced into reactive crisis management by a partner willing to deploy coercive migration tactics in pursuit of territorial recognition.
Normatively, this raises difficult questions. Can the EU continue to project itself as a “normative power” while relying on transactional migration deals that reward authoritarian practices and erode legal safeguards? The evidence suggests that the costs of such pragmatism are mounting: political concessions, reputational damage, and the risk of incentivising further coercive behaviour. Reconciling the EU’s migration management strategies with its foundational values is therefore not only a matter of credibility but also of long-term strategic resilience.

Finally, the findings open important avenues for future research. Comparative studies are needed to assess whether similar strategies are deployed by other transit states in North Africa, the Sahel, and beyond, and to identify the conditions under which coercive migration proves successful or fails. More systematic, possibly quantitative, analyses could map the correlation between border incidents and foreign policy shifts, testing the durability of migration as a coercive instrument. Normative inquiry also remains crucial: if the EU continues to rely on external partners for migration governance, what does this imply for its identity as a values-based actor in global politics?
In sum, the Ceuta crisis should not be dismissed as an isolated border incident. It is emblematic of a broader transformation in international politics where migration has become an instrument of geopolitical bargaining. Recognising and addressing this reality is vital if the EU is to design policies that are both strategically resilient and normatively consistent.

Acknowledgements

Use of generative artificial intelligence (GenAI): This condensed English-language version of the original master's thesis was prepared by the author with editorial support from OpenAI’s ChatGPT-4.5. The generative tool was used exclusively for language refinement and structural guidance in converting the original Dutch-language document into an English-language academic article. GenAI produced no data generation, analytical claims, or factual assertions. All content was critically reviewed and verified by the author to ensure academic integrity.

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