When images of crowded boats crossing the Aegean Sea began to dominate European news in 2015, the European Union faced one of the most dramatic migration crises in its history. Hundreds of thousands of people—many fleeing the war in Syria—were making their way through Türkiye towards Greece and onwards to Central Europe. The crisis not only strained EU border systems but also sparked fierce political debates within Member States about migration and security.
In response, the European Union turned to a crucial partner on its south-eastern flank: Türkiye. The result was the EU–Türkiye Statement of March 2016, an agreement designed to curb irregular migration flows via Türkiye into the European Union. A decade later, the deal has profoundly reshaped migration management in the region, turning Türkiye into what many analysts describe as Europe’s gatekeeper.
Today, due to the ongoing conflicts in the Middle East, crossing points along the Türkiye–Iran border are experiencing an increase in transit migration. Although the situation is far from that of 2015, it highlights the importance of the country in managing migration flows from the East.
More than ten years ago, the migration crisis of 2015 caught both the EU and Türkiye unprepared. The latter was dealing with a renewed war on terror against the Islamic State and the Kurdistan Workers’ Party (PKK), while also preparing for a general election held on 1 November 2015. In this context, the departure of thousands from the Turkish border towards Greece was not a central concern for a country that had already hosted millions of Syrians since the outbreak of the Syrian civil war in 2011.
Nevertheless, the EU was even less prepared to handle mass irregular migration. Following a miscommunicated declaration by the German government regarding the reception of Syrian refugees, Greece and subsequently Central European countries, such as Hungary, had to cope with hundreds of thousands of irregular border crossings in a very short time. In 2015 and early 2016, more than one million people arrived irregularly in Greece via Türkiye. Heated debates emerged within the Union on how to address the crisis. The Hungarian government decided to erect fences along its southern border in order to protect the country and redirect migration flows; after several weeks and months of criticism, other Central European countries also began to restrict and control this migration wave.
Simple border restrictions did not appear to offer a lasting solution, so the EU turned to Türkiye, the key country in this crisis. After months of negotiations, the EU and Türkiye agreed on a joint action plan that became the 18 March 2016 migration deal, known as the EU–Türkiye Statement. The agreement had several key elements. Migrants arriving irregularly in Greece after March 2016 could be returned to Türkiye. For every Syrian returned, another Syrian refugee would be resettled from Türkiye to the EU under a ‘one-for-one’ mechanism. In return, the EU promised financial assistance for refugees in Türkiye, progress towards visa liberalization for Turkish citizens, and renewed momentum in accession negotiations.
The immediate impact was dramatic. Within a year, irregular crossings in the Aegean dropped sharply. What had been one of the busiest migration routes into Europe became significantly quieter. The agreement also illustrated a broader development in European migration policy: the growing tendency to manage migration beyond the EU’s own borders. Stable—or at least manageable—relations with Türkiye remained central to European migration policy. The general framework was maintained despite several crises, such as in early March 2020, when several thousand migrants attempted to cross from Türkiye into Greece at the land border but were repelled by Greek authorities, bringing the situation to a relatively swift end.
Ten years after the Statement, many mechanisms remain limited and several promises unfulfilled. The resettlement mechanism designed to transfer refugees from Türkiye to Europe has been limited in scale. Although EU countries pledged to accept tens of thousands of refugees under the one-for-one scheme, the total number resettled remains modest compared to the millions living in Türkiye. EU accession negotiations are effectively frozen, no substantial progress has been made in upgrading the EU–Türkiye Customs Union, and visa liberalization has yet to materialize. These shortcomings have fuelled frustration in Ankara, where officials have often argued that the EU has benefited more from the agreement than Türkiye.
However, the financial dimension of the deal has produced tangible results in the form of education programmes, health services, and the Emergency Social Safety Net, which has provided basic financial assistance to millions of Syrians living in Türkiye. In addition to the €6 billion allocated for the 2016–2019 period, a further €6 billion was mobilized to support refugees between 2020 and 2027. This assistance has helped Türkiye to improve conditions for Syrians and to enhance its migration management by strengthening border controls and mechanisms for coping with irregular migration. These efforts bore fruit after 2021, when the withdrawal of US troops from Afghanistan triggered new migration movements towards Türkiye, yet without leading to a major new crisis.
‘The financial dimension of the deal has produced tangible results in the form of education programmes, health services, and the Emergency Social Safety Net’
Today, despite rising instability in the Middle East since late 2023, migration has become a less central issue in the EU–Türkiye agenda and within Türkiye itself. Following the sudden collapse of the Assad regime in Syria in late 2024, the voluntary return of millions of Syrians from Türkiye has become more feasible, given the prospects for lasting peace, reconstruction, and the gradual reintegration of Syria into the international system—importantly, the new administration enjoys the Turkish government’s support.
Consequently, the number of Syrians living in Türkiye has begun to decline. Ten years after the EU–Türkiye deal, their number stands at approximately 2.3 million—more than 1.5 million fewer than at its peak. Although coexistence among different groups is never easy, tensions now tend to be lower within Türkiye itself. In terms of numbers, the changes are striking. Sea and land arrivals from Türkiye to Greece remained below 50,000 in 2025, which stands in sharp contrast to 2015, when the figure reached 860,000, and to 2016, when it was 180,000. However, geography does not change. Türkiye will remain a key country in managing migration flows from the East. As military conflicts and economic crises continue to drive migration in the coming years, the country’s role as Europe’s migration gatekeeper is unlikely to diminish. For both sides, the lessons of the past decade remain clear: managing migration is not only about borders—it is also about managing bilateral relations.
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