Can a criminal court list a person’s past activities that appeared lawful at the time and, years later, consider that person a member of a terrorist organisation? More importantly, if the activities in question consist of acts that do not involve violence in themselves, such as opening an account at a bank, having contact with educational circles, taking part in student activities or maintaining telephone contact with certain individuals, how should it be concluded from these acts that the person knew of an organisation’s violent or terrorist purpose?
The Grand Chamber judgment of the European Court of Human Rights in Yasak v. Türkiye, dated 5 May 2026, seeks to answer a question that appears simple but should also be regarded as fundamental for European criminal law. Although the judgment was delivered in the context of Türkiye’s prosecutions for membership of a terrorist organisation, the principle it sets out goes far beyond Türkiye’s borders.
The Yasak judgment is not a judgment that denies states the power to combat terrorism. States may punish terrorist acts and violent organisations; however, in doing so, they cannot base criminal responsibility on association, contact, social environment or retrospective assumptions. As much as the material elements of the offence, the individual’s mental link with the offence must also be established in an individualised manner.
In this respect, there is one concept at the centre of the judgment: mens rea, that is, the mental element of the offence, the level of knowledge, will and intent of the perpetrator.
The Türkiye context: the transition from past activities appearing lawful to terrorist intent
The background of the Yasak case is one of the gravest political ruptures in Türkiye’s recent history. Following the attempted coup of 15 July 2016, Turkish authorities held the Gülen movement, which had long been present in the fields of education, media, finance and civil society, responsible for the attempted coup and characterised the movement as an armed terrorist organisation called “FETÖ/PDY.” As also stated in the ECtHR judgment, the Gülen movement had long been perceived in Turkish society as a religious and educational movement, but especially after 2013 the assessment of state authorities and the judiciary changed, and the formal classification of the organisation as a terrorist organisation by the courts essentially took place in the 2016–2017 period.
This historical context is important. This is because a significant part of the activities relied on for the conviction of the applicant, Şaban Yasak, relates to the period before or during this critical transformation in the social perception and legal characterisation of the structure in question. The applicant was convicted of membership of an armed terrorist organisation under Article 314/2 of the Turkish Criminal Code. The grounds for the conviction included his alleged role within the educational/student structure, account movements at Bank Asya, the payment of his social security contributions by a company considered to be linked to the movement, witness statements and HTS data concerning telephone contact with one person.
Each of these pieces of evidence reflects a familiar pattern seen in many similar cases in Türkiye. In this context, the real problem is through which legal and logical bridge these acts were transformed into “intent to be a member of a terrorist organisation.”
Can a person automatically be considered someone who knew the violent or terrorist aims of an organisation and acted with that purpose because of an account at a bank that was legally operating at the time, because of contact with an educational circle, or because of contact with certain individuals? The Grand Chamber’s answer in the Yasak judgment is, to a large extent, an answer to this question.
From the Chamber to the Grand Chamber: the dramatic weight of the judgment
One of the elements that increases the importance of the Yasak judgment is the judicial transformation within the ECtHR itself. In its judgment of 27 August 2024, the Second Section declared the applicant’s complaints under both Article 3 and Article 7 admissible but unanimously found no violation under either article. The Grand Chamber, however, reached a different conclusion in the same case: it found a violation of Article 7 by 11 votes to 6, and a violation of Article 3 by 9 votes to 8.
This transformation shows how borderline the case was and how legally weighty the matter it contained was. In the same case in which the Chamber unanimously found no violation, the Grand Chamber accepted that two fundamental guarantees of the Convention had been violated: the principle of no punishment without law under Article 7, and the prohibition of ill-treatment under Article 3.
When these two violations are read together, the judgment concerns not only the legal basis of the conviction but also the conditions in which the sentence was served. The conclusion reached by the Grand Chamber under Article 3 relates to the cumulative effect of prison conditions reaching the threshold of degrading treatment. However, the real value of the Yasak judgment for European criminal law lies in the mens rea analysis conducted under Article 7.
The heart of the judgment: rejection of “guilt by association”
In the Yasak judgment, the Grand Chamber clearly emphasised that criminal responsibility cannot be established through collective guilt or mere association. In one of the most critical parts of the judgment, the Court stated that criminal responsibility must be individualised, and that this requires the accused’s mens rea to be clearly established.
This is an important distinction for offences of organisational membership. This is because, in membership offences, criminal responsibility is often established not on the basis of a direct act of violence, but through more indirect indicators such as affiliation, continuity, will, knowledge and commitment. In such offences, courts must move from material acts to the mental element of the perpetrator. The risk of arbitrariness begins precisely here.
What the Yasak judgment says is this: if courts are to move from seemingly lawful or ambiguous activities to terrorist intent, they must establish this transition not by assumption, but through concrete, individualised and temporally meaningful reasoning.
The applicant’s alleged role in the field of education does not, by itself, show his personal, functional or hierarchical link with the organisation’s strategic, violent or terrorist branches. Nor does a bank account, a social security record or telephone contact prove, by itself, that the person knew of the organisation’s violent aims. Therefore, listing acts is not enough. The court must show, with concrete evidence, how it reached criminal intent from those acts.
Article 6 or Article 7? The value of the dissenting opinions
One of the most interesting aspects of the Yasak judgment is the six dissenting votes under Article 7. These dissenting opinions do not reduce the importance of the judgment; on the contrary, they reveal its real weight within the European Convention on Human Rights system.
The dissenting judges do not defend the approach of the domestic court. Their objection is more institutional and more theoretical: if Article 314 of the Turkish Criminal Code is, at a general level, an offence that requires mens rea and is considered foreseeable, then the failure of the court in the specific case to properly discuss this mens rea element is not an Article 7 issue, but, if anything, an Article 6 issue. In other words, according to the dissenting judges, the problem belongs not to the principle of “no punishment without law,” but to the field of the right to a fair trial, reasoned judgment and assessment of evidence. This point is clearly expressed in the joint dissenting opinion: if there was a defect, that defect should have been examined under Article 6; however, there was no admissible Article 6 complaint before the Grand Chamber.
If the ECtHR comes too close to assessing concrete evidence under Article 7, the debate over whether the Court is acting as a “fourth-instance court” becomes inevitable. The ECtHR is normally not an appellate court that replaces national courts and re-examines evidence. The warning of the dissenting judges stems from a concern to preserve this boundary in the architecture of the Convention.
However, the majority’s response is at least as strong as this objection. According to the majority, the issue is not merely whether the domestic court wrote better reasons. If the court automatically infers terrorist intent from past activities that were lawful or ambiguous in nature, without ever individualising the constitutive mental element of the offence, then the problem is no longer confined to the fairness of the trial. This amounts to punishment without establishing a mental link between the perpetrator and the offence. In such a situation, the principle of nulla poena sine culpa, no punishment without fault, which lies at the core of Article 7, comes into play.
Therefore, the 11-to-6 split in the Yasak judgment should not be misread. This division is not about whether the domestic court’s conviction was correct. The real divergence concerns which article of the Convention system should be used to define the same serious defect: Article 6 or Article 7?
This debate shows the legal value of the judgment.
Is Yasak a continuation of previous case law or a new threshold?
The Yasak judgment did not introduce the concept of mens rea into ECtHR case law for the first time. The ECtHR had previously delivered important judgments on personal responsibility, fault and the mental link between the perpetrator and the act in punitive sanctions. In particular, the Sud Fondi and G.I.E.M. line of case law showed that Article 7 is not limited to non-retroactivity; punitive sanctions cannot be imposed without establishing personal responsibility.
In the Türkiye context, the Kavala judgment constitutes an important precedent. In Kavala, the ECtHR stated that it was not possible to move from non-violent civil society activities to a suspicion of attempting to overthrow the government by force and violence, and that those activities largely concerned the exercise of rights protected under Articles 10 and 11 of the Convention. The Court concluded that, in the absence of concrete facts, information or evidence, it could not be reasonably suspected that the applicant had attempted to overthrow the government by force and violence.
However, Yasak takes this line to a different stage. In Kavala, the issue was whether there was reasonable suspicion for detention. In Yasak, the issue was whether a final conviction had been established without individualising the mental element of the offence. Therefore, the novelty of Yasak is not that it says for the first time that an automatic transition cannot be made from lawful activities to a serious criminal accusation. The novelty lies in placing this approach within the guarantee of personal fault and mens rea under Article 7.
In other words, the Yasak judgment says this: even if the legal norm is accepted as foreseeable at a general level, if the transition from concrete acts to criminal intent has not been individualised, this may create an Article 7 problem.
This is an important threshold for criminal law.
The consequence for Türkiye: a new defence ground in TCC 314 proceedings
The most concrete consequence of the Yasak judgment for Türkiye is that it places the mens rea question at the centre of the defence in organisational membership proceedings under Article 314 of the Turkish Criminal Code.
In Türkiye, especially in the post-15 July period, it has been observed that criminal intent has been inferred from lawful or ordinary activities in organisational membership proceedings: acts such as depositing money in a bank, being a member of a trade union or association, working at a school, being in contact with certain people, using a phone application, staying in a student house or being part of a social circle have become part of the accusation of membership of an organisation in many case files.
The Yasak judgment is not a general acquittal ruling that invalidates this practice altogether. It would also be wrong to read it that way. The judgment does not remove the state’s power to collect evidence and punish real organisational commitment. However, it requires courts to do the following: if intent to be a member of a terrorist organisation is to be inferred from these acts, it must be shown when, how and by which concrete evidence the perpetrator knew of the organisation’s violent or terrorist aims.
From now on, the central questions for defences in Türkiye are as follows:
Did this person know the criminal or violent aim of the organisation? On what date did he know this? By what evidence was this knowledge established? How were the alleged activities linked to the strategic or violent structure of the organisation? How did the court establish the transition from apparently lawful or ambiguous activities to criminal intent?
A conviction delivered without answering these questions can no longer be seen merely as a poorly reasoned decision. After the Yasak judgment, this amounts to punishing a person without establishing their mental link.
The consequence for Europe: a preventive standard for 46 states
The importance of the Yasak judgment is not limited to Türkiye. The Council of Europe is today a system of 46 members, and although Grand Chamber judgments of the ECtHR are formally binding on the respondent state, they produce a strong and authoritative European standard for all member states in terms of the interpretation of the Convention. Under Article 46 of the European Convention on Human Rights, States Parties undertake to abide by final judgments of the ECtHR in cases to which they are parties; the execution of judgments is also supervised by the Committee of Ministers.
For this reason, Yasak should not be read solely as a product of Türkiye’s post-15 July proceedings. Türkiye may represent one of the most intense and visible examples of this problem; however, across the Council of Europe region, it is increasingly seen that different governments frame civil society activities, protest movements, foreign-funded organisations, independent journalism or political opposition through the language of “national security,” “foreign influence” or “public order.”
In Azerbaijan, the Council of Europe Commissioner for Human Rights has called for the release of human rights defenders, journalists and civil society activists and expressed concern over the imprisonment of these individuals because of their legitimate work or critical views. In Georgia, the Venice Commission has examined legislation concerning foreign agents and foreign influence; this legislation has been the subject of serious European debates in terms of placing civil society activities within a security-based framework. In Serbia, the Council of Europe Commissioner for Human Rights conducted a special mission concerning the management of demonstrations by the police and the working environment of civil society and human rights defenders.
None of these examples is identical to Türkiye. However, the Europe-wide meaning of the Yasak judgment emerges here: when states act through the language of security, public order, foreign influence or counter-terrorism, and seek to transform lawful or civil activities into evidence of serious criminal intent, they must show personal fault and mens rea in an individualised manner. Association, contact or social environment cannot replace fault.
Hungary connects to this debate from a different angle. Following the 2026 elections, the end of Viktor Orbán’s 16-year rule and the strong parliamentary majority obtained by the Tisza Party under the leadership of Péter Magyar brought debates on rule-of-law reforms, the fight against corruption and the release of frozen EU funds to the agenda. Reuters reported that Magyar held talks with the European Commission on rule-of-law and anti-corruption steps for the release of EU funds. Reuters also reported that, following the Orbán period, debates on accountability had begun concerning major media/communications actors associated with state campaigns and public contracts.
The Hungarian example shows that the Yasak judgment speaks not only to the risk of current governments using criminal law against opponents, but also to the need for accountability processes during political transitions to remain within the law. The fight against corruption, the investigation of misuse of public resources and the restoration of the rule of law may be legitimate and necessary. However, political proximity, institutional affiliation or being part of a former ruling network cannot replace personal fault. The principle that protects opponents from “guilt by association” also keeps transitional accountability within the limits of the rule of law.
For this reason, the Yasak judgment is not only a warning against repressive criminal practices; it is also a rule-of-law warning directed at new administrations that claim democratic restoration.
Conclusion: the state may punish, but it cannot establish guilt by assumption
Yasak v. Türkiye has made visible once again the following fundamental principle of European criminal law: criminal responsibility is not collective; it cannot be established automatically through association, environment, contact or the later reinterpretation of past lawful activities. States may combat terrorism. They may punish violent organisations, real criminal complicity and conscious participation. However, in doing so, they must concretely show that the person knew the organisation’s criminal or violent aim and acted with that purpose.
This is the most important defence tool that the Yasak judgment leaves to lawyers in Türkiye: courts must be asked not merely to list evidence, but to explain how they move from evidence to mens rea.
The broader legacy that the judgment leaves to Europe is this: when modern states, in the name of security or accountability, begin transforming past lawful, civil or ambiguous activities into evidence of serious crimes, the most fundamental principle that will protect the individual is the principle of personal fault.
The Yasak judgment has reaffirmed this principle not merely as a theoretical concept of criminal law, but as an enforceable guarantee under Article 7 of the European Convention on Human Rights.
For this reason, the judgment does not concern only Şaban Yasak’s case. It is important for thousands of organisational membership proceedings in Türkiye. For the 46 member states of the Council of Europe, it also serves as a broader warning: the rule of law is not protected merely by defining offences in law. It is also protected by showing, in an individualised manner, that the person punished truly committed that offence knowingly and willingly.