Broadening the Yalçınkaya Precedent: The Grand Chamber Judgment in Yasak v. Türkiye

By dr. Ufuk Yeşil

Introduction

On May 5, 2026, the Grand Chamber of the European Court of Human Rights (ECtHR) delivered its judgment in the case of Yasak v. Türkiye (Application No. 17389/20). By a majority, the Court held that the conviction of the applicant under Article 314 § 2 of the Turkish Penal Code (TCK) for membership in an armed terrorist organization violated the principle of nullum crimen sine lege (no punishment without law) under Article 7 of the Convention. Additionally, the Court found a violation of Article 3 regarding the applicant’s detention conditions at Çorum Prison.

The legal and doctrinal significance of this ruling must be understood within the macro-context of the mass anti-terror trials conducted in Türkiye following the coup attempt of July 15, 2016. In its landmark judgment in Yüksel Yalçınkaya v. Türkiye (2023), the Grand Chamber leveled systemic critiques against the domestic judiciary’s application of anti-terror legislation, explicitly pointing out that tens of thousands of applications and domestic files shared identical structural flaws.

The case of Yasak v. Türkiye emerges as a direct reflection of this widespread, systemic pattern of anti-terror prosecutions. Despite the comprehensive principles established in Yalçınkaya, the persistence of these domestic judicial practices forced the Grand Chamber to revisit this structural issue. In doing so, the Grand Chamber explicitly set aside the Second Section’s Chamber judgment of August 27, 2024—which had originally found no violation—using the Yasak case to further consolidate its case law and strictly define the substantive requirements of personal culpability and intent (mens rea) under Article 7.

Context and Facts of the Case

The applicant, Şaban Yasak, was an educator who worked as a voluntary student mentor and regional supervisor within a Gülen-linked educational network in Çorum between 2011 and 2014, and was employed by a state-licensed corporate entity, Çorum Eğitim Hizmetleri A.Ş. On February 14, 2018, the Çorum Assize Court sentenced the applicant to seven years and six months’ imprisonment for membership in an armed terrorist organization under Article 314 § 2 of the TCK (§ 70).

The domestic courts based their conviction on a cumulative assessment of several evidentiary elements:

• Witness testimonies regarding regional leadership and organizational nomenclature: The domestic courts relied on statements from witnesses who had availed themselves of domestic effective repentance provisions (§ 70). These witnesses alleged that the applicant operated as a “principal regional student leader (BTM-BBTM)” within the educational networks of the Gülen Movement and actively utilized the underground code name “Recep” (§ 70). The domestic courts treated this alleged use of a pseudonym as explicit evidence of structural integration and clandestine intent (mens rea), rather than routine involvement in lawful educational activities (§ 70).
• Employment history: Social security (SGK) records indicating professional employment at an organization affiliated with the Gülen Movement (Çorum Eğitim Hizmetleri A.Ş.) (§ 70).
• Banking transactions at Bank Asya: A commercial deposit gateway that, at the material time, operated legally under state banking regulations (§ 70). The domestic court retrospectively treated routine transactions—specifically a deposit of 2,000 Turkish liras (TRY) made after a December 2013 public appeal by the movement’s leadership—as deliberate financial support for an illegal organization, irrespective of the bank’s lawful status at the time (§ 70).
• Telecommunications metadata: Historical Traffic Search (HTS) records logging telephonic contacts with other suspected individuals under investigation (§ 70).

Following his conviction, the applicant was detained for over four years at Çorum Prison. He subsequently lodged an application with the ECtHR, alleging that the domestic courts’ interpretation of the material and mental elements of the offense violated Article 7, and that the severe overcrowding of his place of detention breached Article 3.

In the initial stage of the proceedings, the Second Section unanimously held on August 27, 2024, that there had been no violation of either provision. This Chamber judgment, however, incited significant doctrinal debate, notably being voted “The Worst ECtHR Judgment of 2024” in the annual poll conducted by Strasbourg Observers in early 2025.

Following a referral request by the applicant under Article 43 of the Convention, the case was referred to the Grand Chamber on December 16, 2024. Following a public hearing on May 7, 2025, the Grand Chamber rendered its final judgment on May 5, 2026, ultimately reversing the Chamber’s findings on both articles.

The Grand Chamber’s Assessment of Article 7: Codifying the Substantive Requirement of Mens Rea

The central issue before the Grand Chamber under Article 7 was whether the interpretive methodology used by the domestic courts to establish the applicant’s mens rea (criminal intent), prior to convicting him of membership in an armed terrorist organization, was compatible with the Convention (§ 204). The Court set the foundational tone by anchoring Article 7 as an absolute, non-derogable pillar of the rule of law (§ 190). It clarified that the principle of legality goes far beyond a mere prohibition on retroactive punishment; it demands that offenses be clearly defined, accessible, and objectively foreseeable, thereby serving as an effective safeguard against arbitrary prosecution (§ 191).

Drawing heavily from Yüksel Yalçınkaya v. Türkiye, the Grand Chamber codified that Article 7 protects individuals from being punished without personal liability being established under the core maxim of nulla poena sine culpa (§ 193). This mandate requires domestic courts to prove both the material acts (actus reus) and a distinct mental link (mens rea), ruling that any judicial maneuver bypassing this mental element impermissibly converts a crime into a strict liability offense (§ 193, § 195).

In applying these rigorous principles to the present case, the Grand Chamber exposed a fundamental structural flaw in how the domestic judiciary evaluated the applicant’s criminal intent:

• The Presumption of Intent via Historical Association: The Grand Chamber observed that the domestic courts failed to establish the mental element required under Turkish law through an individualized and contextual analysis (§ 112, § 212). Instead, the Çorum Assize Court relied extensively on macro-considerations regarding the historical development of the Gülen Movement from a religious and educational group into an entity subsequently designated as a terrorist organization (§ 70, § 211). Because the organisation had been embedded within Turkish society for a considerable period, operating legally as a highly visible “moral and educational movement,” thousands of ordinary citizens maintained ties with its structures (§ 204, § 208). The domestic judiciary completely failed to bridge the gap between group history and individual culpability; it merely listed the items of evidence and automatically jumped to the conclusion that mens rea was present, without proving that the applicant joined or maintained links with the group in full knowledge of its illegal, transformed nature (§ 211).
• The Retroactive Criminalization of Lawful Acts: Furthermore, the majority emphasized the critical importance of the temporal framework of the offense (§ 204). The bill of indictment lacked necessary rigour and failed to clearly isolate the specific timeframe of the applicant’s alleged membership, which the ECtHR deduced had ended sometime in 2014 (§ 205). At the public hearing, the Government conceded that none of the individual actions imputed to the applicant—such as applicant’s role as an educational supervisor (BBTM) or routine banking transactions at Bank Asya—were prohibited by law at the material time (§ 207). By treating regular participation in civil, economic, and educational life as immediate, retrospective proof of subversion, the domestic courts effectively applied an impermissible standard of strict or objective criminal liability, a practice explicitly prohibited under Article 7 (§ 195, § 211).
• The Obliteration of the ‘Mental Link’: To legally convert these facially benign, non-violent acts into a conviction for membership under Article 314 § 2 of the TCK, the domestic courts were under a strict obligation to establish a clear “personal, functional, or hierarchical link” between the individual and the organization’s strategic, operational branches (§ 126, § 209). The Grand Chamber rejected the state’s argument that because the applicant held a regional student supervisor role (BBTM), he “could have anticipated” the existence of covert cells within the military (§ 209). Article 7 demands concrete evidence of personal intent, not hypothetical speculation (§ 209). Instead of verifying an actual, conscious link connecting the applicant to the organization’s terrorist objectives, the domestic courts simply substituted his educational role for proof of subversion, entirely ignoring his placement within the multi-layered hierarchy recognized under domestic case law (§ 209-210).

This positioning, however, exposed a deep doctrinal rift within the Court. In her notable dissenting opinion, Judge Ní Raifeartaigh cautioned that by using Article 7 to enforce a self-standing requirement of mens rea, the majority has taken a bold step toward altering the Court’s traditional mandate (Dissenting Opinion of Judge Ní Raifeartaigh, § 4-7). She argued that reviewing whether evidence proves a defendant’s intent belongs properly under the fair trial guarantees of Article 6, rather than pushing ECtHR into dictating the substantive boundaries of domestic criminal law.

The other 6 dissenting judges on Article 7 (which included Judge Yüksel and Judge Seibert-Fohr, among others) shared the structural concerns articulated by Judge Ní Raifeartaigh. Their collective stance was that by checking whether the domestic file contained enough specific evidence to establish mens rea, the majority went beyond checking the legality of the law (Article 7) and instead acted as a “Fourth-Instance Court”—essentially re-evaluating facts and evidence, which is a procedural task historically reserved for Article 6.

Ultimately, the Grand Chamber determined that the total absence of a meaningful, individualized explanation as to how the mens rea was determined violated the applicant’s fundamental rights (§ 212). By failing to establish a concrete mental link through which an element of personal liability could be detected, the domestic courts applied criminal law in an arbitrary and unforeseeable manner, resulting in a distinct violation of Article 7 of the Convention (§ 213).

The Article 3 Threshold: Prison Overcrowding and the Cumulative Effects Test for Severe Suffering

The Grand Chamber was narrowly divided on the question of whether the applicant’s conditions of detention at Çorum Prison crossed the minimum threshold of severity to constitute degrading treatment under Article 3. By a thin 9-to-8 majority, the Court concluded that a violation had occurred, focusing heavily on the cumulative physical and psychological toll of prolonged overcrowding and inadequate sleeping arrangements (§ 175-179).

The Grand Chamber concluded that the conditions of detention at Çorum Prison crossed the threshold of degrading treatment, constituting a distinct violation of Article 3 of the Convention (§ 240). Although the applicant’s personal space did not trigger a strict structural presumption of a violation under the Muršić framework, the Court’s assessment focused heavily on the cumulative physical and psychological toll of a facility operating under manifest overcrowding, packed with up to 2,000 inmates against a maximum capacity of 1,592 (§ 240). For a prolonged and continuous period of four years, the applicant endured severely strained sanitary facilities, limited outdoor exercise in a cramped courtyard, and the exceptional precariousness of spending a total of fourteen months sleeping on a floor mattress in communal areas (§ 240-241). Deprived of an individual bed and subjected to a total lack of privacy, constant artificial night lighting, and structural noise, the applicant suffered intense physical and mental fatigue (§ 241).

The Court explicitly emphasized that this prolonged exposure could not be brushed aside as a temporary or occasional grievance (§ 242). Ultimately, the Grand Chamber determined that the cumulative effect of these compounding deficiencies subjected the applicant to an exceptional physical and psychological burden that far exceeded the unavoidable level of suffering inherent in detention, decisively attaining the minimum level of severity required to violate Article 3 of the Convention (§ 242-243).

However, a powerful joint partly dissenting opinion—supported by eight judges (Vehabović, Schukking, Chanturia, Yüksel, Seibert-Fohr, Roosma, Guerra Martins, and Ní Raifeartaigh) —vigorously challenged the majority’s application of the Court’s own established jurisprudence in Muršić v. Croatia (2016) (Joint Dissenting Opinion, § 12-15). Under the Muršić framework, a “strong presumption” of an Article 3 violation is triggered only when an inmate’s personal space falls below 3 square meters. The dissenters pointed out that the applicant’s actual personal space ranged from 3.6 to 4.6 square meters in Unit F-5, and reached up to 6 square meters in Unit F-10 (§ 165). Consequently, no presumption of a violation existed.

Doctrinal Evolution: Beyond the Yalçınkaya Framework

The systemic significance of Yasak v. Türkiye lies in its consolidation and expansion of the principles set forth in Yüksel Yalçınkaya v. Türkiye (2023). While Yalçınkaya focused heavily on the procedural shortfalls of relying on mass data under Article 6, Yasak shifts the analytical weight squarely onto the substantive requirements of Article 7 (§ 140). By establishing that a failure to rigorously assess mens rea directly triggers a violation of the principle of legality, the Grand Chamber has fortified the barrier against strict or objective criminal liability in terror-related offenses (§ 142).

Crucially, the judgment addresses an ongoing domestic interpretive methodology where individual criminal responsibility and the predictability of criminal law are critically tested (§ 145). The Court’s reasoning reaffirms that the structural flaws identified in Yalçınkaya were not confined to specific digital evidence, but rather stemmed from a broader judicial practice of conflating the material (actus reus) and mental elements of membership offenses—effectively treating participation in facially lawful activities as retrospective proof of criminal intent (§ 148).

The ruling codifies a strict evidentiary threshold: domestic courts cannot deduce criminal intent from regular participation in civil, educational, or commercial activities—such as voluntary student supervision, routine banking transactions, or standard employment records—that bore the appearance of legality at the material time (§ 152). To bridge the gap between lawful social action and criminal accountability, the Court now mandates a demonstrated personal and operational nexus to the illegal objectives of an armed group (§ 155). This represents a significant development in ECHR law, moving from procedural oversight of domestic evidence to a substantive policing of how domestic courts structure the elements of accountability under Article 314 § 2 of the TCK (§ 158).

The Just Satisfaction Controversy: A Remedy Deferred?

The judgment also exposed a sharp procedural disagreement regarding the implementation of remedies under Article 41 of the Convention. By an 11-to-6 majority, the Grand Chamber held that the finding of a violation of Article 7 constituted in itself sufficient just satisfaction for any non-pecuniary damage sustained by the applicant (§ 245). The majority reasoned that the most appropriate avenue for redress remains the reopening of domestic proceedings under Article 311 § 1 (f) of the Turkish Code of Criminal Procedure (CMK), an approach echoing recent precedents such as Delga v. France (2024) and Demirhan and Others v. Türkiye (2025) (§ 246).

This position drew a sharp dissent from Judge Guerra Martins, who criticized the Court’s increasing reliance on domestic retrials as a substitute for moral compensation. Judge Martins asserted that a judge is not strictly bound by recent, non-participating formations, arguing that the refusal to award monetary damages for a substantive Article 7 violation leaves an applicant’s past moral injury and prolonged detention uncompensated (Dissenting Opinion of Judge Guerra Martins, § 8-11). This debate underscores a broader, ongoing institutional tension within Strasbourg regarding whether the Court should provide immediate financial satisfaction or rely entirely on domestic judicial architectures to execute its rulings under Article 46.

Conclusion

What makes the Yasak judgment particularly crucial in terror-related offenses is the Grand Chamber’s definitive ruling that criminal intent (mens rea) for membership in an armed terrorist organization cannot be retroactively deduced from routine and entirely lawful past actions carried out within a civic or social group that only subsequently transformed into a terrorist entity. Through this landmark ruling, the Grand Chamber has detailed, in an explicit and striking manner, the exact substantive criteria that domestic courts must rigorously establish under Article 7 to meet the mental element required for this offense.

By reclassifying neutral social and financial interactions—such as voluntary activities, legal employment, communication records, and banking transactions—as criminal conduct, the domestic courts exceeded the limits of acceptable judicial interpretation. In doing so, they effectively bypassed the requirement of mens rea and violated the principle of objective foreseeability.

Through this new ruling, the Grand Chamber has consolidated the criteria set out in Yalçınkaya, making them more systematic and comprehensive. By demanding an individualized, context-specific, and temporally limited evaluation of criminal liability, the Court has strongly reinforced the classic tenets of nullum crimen sine lege. Ultimately, these criteria serve as fundamental structural safeguards that must be applied not only to post-July 15 trials, but universally across all terrorism-related adjudications. For Contracting States navigating domestic security crises, Yasak serves as a firm reminder that the exceptional nature of anti-terror operations cannot validate the dilution of personal criminal responsibility.