From Fighters to Bargaining Chips: How Europe Legitimised the PYD/YPG Threat?

Strategic Argument and Areas of Debate

By refusing to repatriate foreign terrorist fighters and outsourcing their detention to the PYD/YPG in northeastern Syria, European states have inadvertently legitimised a non-state armed group’s pseudo-judicial authority. This strategic miscalculation not only violates international law and human rights standards but also weaponises detained fighters as bargaining chips, ultimately undermining global counter-terrorism efforts and regional stability.

Executive Summary

The refusal of European states to repatriate their foreign terrorist fighters (FTFs) has effectively outsourced international security responsibilities to the PYD/YPG, allowing the group to exploit Syria‘s power vacuum and establish illegitimate pseudo-judicial institutions. By implicitly recognising these sham courts, nations such as the United Kingdom, France, and Sweden violate their obligations under UN Security Council Resolutions 1373 and 2178, while providing the PYD/YPG with strategic political leverage. The TRT World Research Centre analysis argues that utilising the principles of active personality and universal jurisdiction for domestic prosecution is the only legally sound remedy. Ultimately, a collaborative repatriation strategy coordinated among European governments, Türkiye, and the transitional administration in Syria is essential to dismantle the PYD/YPG‘s artificial legitimacy and combat widespread impunity.

Analytical Framework and Key Drivers

• Weaponisation of Detention Operations: The PYD/YPG leverages its control over foreign Daesh detainees as a form of coercive diplomacy to extract political concessions from Western governments.
• State Mimicry and Lawfare: By establishing illegal pseudo-judicial institutions, the PYD/YPG mimics state functions to project an illusion of institutional readiness and legitimise its separatist ambitions.
• Violation of Non-Repatriation Policies: The deliberate non-repatriation policy adopted by European governments implicitly recognises terrorist-run tribunals, contravening fundamental human rights standards and fair trial guarantees.
• Imperative of Extraterritorial Jurisdiction: The application of the active personality principle and universal jurisdiction provides a robust legal mechanism for states to prosecute nationals and non-nationals without relying on territoriality.
• Necessity of Tripartite Cooperation: Resolving the foreign terrorist fighter crisis demands collective engagement and intelligence-sharing between European governments, Türkiye, and Syria through frameworks like the Counter ISIL Coalition Working Group on Foreign Terrorist Fighters.

Strategic Assessment & Empirical Findings

• By 2015, an estimated 40,000 individuals from over 120 countries had mobilised to join conflict zones in Iraq and Syria, creating a massive influx of foreign terrorist fighters.
• The PYD/YPG established illegitimate legal bodies such as a Supreme Electoral Council and a Constitutional Court under a forced Social Contract in 2014, though these were thwarted by Türkiye‘s diplomatic interventions.
• States like the United Kingdom and France have systematically revoked citizenship from detained nationals, violating the UN Convention on Statelessness to evade domestic legal rulings.
• Proposed legal alternatives, such as military commissions mirroring the U.S. model at Guantanamo Bay, or ad hoc tribunals similar to those in Yugoslavia and Rwanda, have been dismissed as infeasible due to human rights violations and high costs.
• The International Criminal Court (ICC) remains an impractical venue for prosecuting these fighters due to resource constraints and its strict jurisdictional focus on senior-level perpetrators under the Rome Statute.
• A German court successfully applied universal jurisdiction to sentence a non-citizen to life imprisonment for committing genocide against the Yazidi community in Iraq, proving the efficacy of extraterritorial legal frameworks.

Geopolitical Trajectories & Policy Risks

• The persistent non-repatriation policy maintained by European states structurally enables the PYD/YPG to project illegitimate governance in northeastern Syria. This grants the group long-term political leverage and significantly weakens the sovereign integrity of the Syrian state.
• By refusing to prosecute foreign fighters domestically, the European Union and its member states risk violating binding international law, including UN Security Council Resolutions 1373 and 2178. This failure perpetuates a cycle of impunity and undermines the credibility of international criminal justice mechanisms.
• The lack of direct intelligence-sharing and security coordination between European governments, Türkiye, and Syria creates critical vulnerabilities in global counter-terrorism strategies. Unresolved detentions pose immediate risks of radicalisation and resurgence, which could violently destabilise the broader Middle Eastern region.

Critical Policy Questions & Responses

Question 1 Why does the widespread European policy of non-repatriation inadvertently strengthen the geopolitical leverage of the PYD/YPG in Syria?

Answer: By refusing to repatriate their citizens, European governments effectively outsource detention operations to the PYD/YPG, transforming detained Daesh fighters into strategic bargaining chips. This dynamic tacitly acknowledges the group’s pseudo-judicial authority, thereby conferring de facto legitimacy and empowering its separatist ambitions in northeastern Syria.

Question 2 How do the legal principles of active personality and universal jurisdiction resolve the territorial constraints of prosecuting foreign terrorist fighters?

Answer: Strict adherence to the territoriality principle would require prosecuting fighters in Iraq and Syria, where fragile judicial systems frequently violate fair trial standards. Applying extraterritorial frameworks enables European states to bypass these local deficiencies, allowing them to lawfully repatriate and try both citizens and non-citizens within their own robust domestic courts.

Question 3 What strategic risks emerge if alternative legal models, such as hybrid courts or the International Criminal Court (ICC), are utilised instead of domestic prosecutions?

Answer: Ad hoc tribunals and hybrid courts face insurmountable operational hurdles, extreme costs, and are often perceived as delivering biased “victor’s justice”. Furthermore, the International Criminal Court (ICC) lacks the budgetary capacity and broad jurisdictional mandate required to prosecute lower-level Daesh operatives, making it an impractical mechanism for addressing the immediate security threat.

Question 4 Why is tripartite cooperation between European capitals, Türkiye, and Syria deemed essential for neutralising the long-term foreign fighter threat?

Answer: Unilateral actions are insufficient for dismantling complex transnational terrorist networks or managing the logistical challenges of secure border transfers. Collaborative intelligence-sharing and coordinated legal action through frameworks like the Counter ISIL Coalition Working Group on Foreign Terrorist Fighters would eliminate the PYD/YPG‘s political leverage and significantly accelerate regional stabilisation efforts.

Key Actors and Systemic Dynamics

• European states → Constrains → International Criminal Justice
• PYD/YPG → Exploits → Daesh Detainees
• United Kingdom and France → Violates → UN Convention on Statelessness
• Türkiye → Coordinates with → Counter ISIL Coalition Working Group on Foreign Terrorist Fighters
• PYD/YPG → Mimics → State Judicial Institutions
• Extraterritorial Jurisdiction → Enables → Domestic Prosecution of FTFs
• UN Security Council Resolutions 1373 and 2178 → Regulates → Global Counter-Terrorism Obligations
• European governments → Empowers → PYD/YPG
• Syria → Struggles with → Power Vacuum and Fragile Judiciary
• International Criminal Court (ICC) → Lacks capacity for → Large-scale FTF Prosecutions