The Grand Chamber Judgment in S.M. v Croatia: Human Trafficking, Prostitution and the Definitional Scope of Article 4 ECHR

By Dr Vladislava Stoyanova (Associate Professor, Faculty of Law, Lund University)

With S.M. v Croatia, issued on 25 June 2020, the Grand Chamber delivered its first judgment under Article 4 (the right not to be held in slavery or servitude or to be required to perform forced or compulsory labour) concerning inter-personal harm, i.e. circumstances where one private individual has arguably abused another. The referral of the case to the Grand Chamber has to be viewed in light of the powerful and convincing dissenting opinion of Judge Koskelo attached to the Chamber judgment. An opinion, such as Koskelo’s dissent, was well overdue, given the definitional quagmire that the various Chamber judgments under Article 4 have caused. This quagmire started with Rantsev v Cyprus and Russia (see here) and has continued ever since (e.g. see Chowdury and Others v Greece, for an analysis see here and here). In particular, with Rantsev, the Court added ‘human trafficking’ as defined in the Palermo Protocol and the CoE Trafficking Convention, to the conceptual apparatus of Article 4 ECHR. At the same time, it never clarified how the facts of the case actually fit within the definition of human trafficking. Neither did it clarify how the ambiguous terms in the definition itself, such as ‘sexual exploitation’ or ‘the exploitation of the prostitution of others’, are to be interpreted within the context of Article 4 ECHR (for the ambiguity of the definition of human trafficking, see Stoyanova, Human Trafficking and Slavery Reconsidered (CUP, 2017)).

In this blog, I will briefly describe the facts of the case, the findings of the Grand Chamber under the procedural limb of Article 4 ECHR and then I will focus on the efforts by the Grand Chamber to more generally clarify the definitional limits of this provision.


The case concerned S.M., a woman born in 1990, who in September 2012 came to the police station and filed a criminal complaint against T.M. In her complaint, she alleged that T.M. had physically and psychologically forced her into prostitution during the summer of 2011. The applicant clearly came from a vulnerable group (she lived with a foster family and a public home for children). A police investigation followed that included questioning S.M., T.M. and a friend of S.M., and a search of T.M.’s premises and car, where condoms, rifles, ammunitions and mobile phones were discovered. It was also relevant that T.M. already had a criminal record, being previously convicted of procuring prostitution using coercion and of rape. T.M. denied that he forced S.M. into prostitution. He was eventually acquitted by the domestic courts of the charge of procuring prostitution through coercion. The domestic courts concluded that force could not be proven.

Breach of the procedural obligation under Article 4

The Grand Chamber concluded that the criminal investigation by the domestic authorities of the allegations made by S.M. and the subsequent criminal proceedings against T.M., had ‘significant flaws’ to the point of constituting a violation of the procedural obligation under Article 4.  The core of my analysis here is not on the findings concerning the procedural limb of Article 4. However, it can be briefly mentioned that these findings do signal some important developments. One of them concerns the question what triggers an assessment under the ECHR by the Court whether the national authorities have fulfilled their procedural obligation to investigate (para 324-5) (for a thorough analysis of this question, see Stoyanova, Human Trafficking and Slavery Reconsidered page 352). As the Court established in S.M. v Croatia, this trigger does not require that the Court itself makes a finding that the applicant was actually subjected to treatment contrary to Article 4. Rather

when an applicant’s complaint is essentially of a procedural nature as in the present case, it [the Court] must examine whether, in the circumstances of a particular case, the applicant made an arguable claim or whether there was prima facie evidence (commencement de preuve) of her having been subjected to such prohibited treatment. (para 324)

The relevance of Article 4

Interestingly, however, in her complaint S.M. did not invoke procedural flaws under Article 4. Rather, S.M. complained to the Strasbourg Court about the actual application of the national criminal law to her case. In particular, as pointed out by the Joint Occurring Opinion of Judges O’Leary and Ravarani, the heart of the applicant’s complaint was the failure of the national court to reclassify the charge from procurement of prostitution through coercion (that could not be proven) to procurement of prostitution (a lesser form of charge). S.M.’s application to the Court was based on Articles 3 and 8. Article 4 ECHR was not mentioned, which gave the basis for Croatia to raise a preliminary objection.

The objection was dismissed by the Grand Chamber: ‘Her complaints undoubtedly raised an issue which the Court, by virtue of the jura novit curia principle and in view of its case-law, [references omitted] could seek to determine whether it fell to be characterised under Article 4 of the Convention.’ (para 224) The Grand Chamber thus framed the complaint as one raising issues of ‘alleged impunity for human trafficking, forced or alternatively non-forced prostitution relating to a deficient application of the relevant criminal-law mechanisms. It is thus essentially of a procedural nature.’ (para 229)  It then added that these issues are to be examined under Article 4 for two reasons (para 241-2). First, the case law ‘tended to apply Article 4 to issues related to human trafficking.’ Second, this allows the Court the place the alleged abuses ‘into their general context, namely that of trafficking in human beings and sexual exploitation.’

The first reason is essentially circular; it goes along the lines that since the Court has done it before (as previously mentioned, in a particularly doubtful way), it can continue to invoke human trafficking. The second one is more convincing. The invocation of human trafficking does allow the Court to draw on the already developed human trafficking legal framework particularly at regional level within the Council of Europe, where the Anti-trafficking Convention has been adopted that imposes important obligations upon states (see here) and where the work of this Convention’s monitoring mechanism (GRETA) has already made important advancements. Already in Chowdury and Others v Greece (para 104), the Court referred to the work of GRETA.

The importance of GRETA’s work was further confirmed in S.M. v Croatia (para 344).

The concepts within Article 4 and their relationship  

Provoked by the dissenting opinion of Judge Koskelo to the Chamber judgment, the Grand Chamber saw an opportunity to use S.M. v Croatia to more generally clarify the definitional scope of Article 4 in light of the addition of the concept of human trafficking within this provision’s definitional parameters. The Chamber judgment appears to be underpinned by the assumption that Article 4 covers not only human trafficking, but also ‘exploitation of prostitution’ as such without the other constituting elements in the definition of human trafficking (para 54). Another related assumption underlying the Chamber judgment was that prostitution is included within the definitional scope of Article 4 even if the alleged victim has consented since ‘the consent of the victims is irrelevant’ (para 54 and 79).

Here it can be observed that the Chamber was simply following the confusing formulation and reasoning in Rantsev v Cyprus and Russia, where the ECtHR referred to Rantseva as ‘a victim of trafficking or exploitation’ (para 296) (emphasis added). No engagement was undertaken with the question whether  Rantseva was a victim of exploitation within the context of trafficking, which requires linking the exploitation with certain ‘means’ and certain ‘actions’ according to the international law definition of human trafficking. Similarly, an analysis was absent as to whether Rantseva was simply a victim of exploitation, which would imply that the definitional scope of Article 4 was enlarged to such an extent as to cover ‘exploitation’, whatever ‘exploitation’ might mean. It needs to be noted that the interpretative openness of the term ‘exploitation’ is wide enough to cover any forms of prostitution, even forms not involving coercion.

After introducing general clarifications regarding the concepts explicitly indicated in Article 4 (slavery, servitude and forced labour) by drawing on its previous case law, in S.M. v Croatia the Grand Chamber tackled the following two issues (1) the inclusion of human trafficking under Article 4 ECHR; and (2) the inclusion of ‘exploitation of prostitution’ under Article 4.

As to the first issue, the Grand Chamber first clarified that ‘it is not possible to characterize a conduct or a situation as an issue of human trafficking unless it fulfills the criteria for the phenomenon in international law’ (para 290). Then, it felt compelled to further (further than what was done in Rantsev v Cyprus and Russia) justify the inclusion of the concept of human trafficking under Article 4. From my reading, this additional justification has three bases.

First, as a form of abuse, human trafficking is comparable and similar to the abuses of slavery, servitude and forced labour that are explicitly mentioned in Article 4. The Grand Chamber held that ‘the identified elements of trafficking […] cut across the three categories set out in Article 4’ (para 291). It added that the conclusion that ‘trafficking in human beings run counter to the spirit and purpose of Article 4’ ‘finds support in the comparison of the essential elements of the concepts enunciated in Article 4, as construed in the Court’s case law and the constituent elements of the phenomenon of human trafficking’ (para 293).

Correct, human trafficking, as defined in international law, might be comparable with slavery, servitude and forced labour in some respects (Stoyanova, Human Trafficking and Slavery Reconsidered page 292). However, there is no convergence. In addition, human trafficking does seem to be a more expansive concept in terms of requiring a lower threshold of severity of the abuses involved. In addition, one can still remain to wonder why human trafficking needs to be included in Article 4, when this provision might already have the concepts to cover relevant abuses.

Notably, nothing has been done so far by the Court to clarify the relationship between human trafficking on the one hand, and slavery, servitude and forced labour, on the other. In some judgments, the Court has conflated human trafficking and forced labour (e.g. Chowdury and Others v. Greece, see here). In other judgments, Court has conflated human trafficking and slavery by defining the former through the definition of slavery in international law (see para. 281 of Rantsev, see here).

The second justification invoked by the Grand Chamber for including human trafficking under Article 4 concerns the International Labour Organisation (ILO) (para 293). The argument here is that since the ILO has conflated human trafficking and forced labour, the ECtHR can adopt the same, in my opinion (Stoyanova, Human Trafficking and Slavery Reconsidered page 37), erroneous approach. In addition, the ILO position is that ‘trafficking in persons for the purpose of exploitation is encompassed by the definition of forced or compulsory labour’ (para 145). This position ignores the differences between the two concepts. In addition, it also seems to defeat the purpose of including the concept of human trafficking. If the abuses meant to be covered by this concept are already encompassed by the concept of forced labour, why should the former be added?

The third justification invoked by the Grand Chamber for including human trafficking under Article 4 is based on comparative law material: ‘there is universal recognition of human trafficking as a serious crime that involves, inter alia, sexual exploitation. Indeed, all thirty-nine Council of Europe member States for which the comparative information is available criminalize human trafficking.’ (para 293) Indeed, the human trafficking legal framework (originating from the UN, the Council of Europe and the EU levels) has had a very strong impact on the national substantive criminal law and, as a consequence, states have criminalized human trafficking. This, however, does not mean that there is anything close to a uniform or a common interpretation of human trafficking across national jurisdictions. The national authorities in some countries tend to interpret the crime very widely, including by having removed the ‘means’ element of the human trafficking definition and/or viewing any involvement in voluntary prostitution as human trafficking (see here and Chapter 13 here). It follows that references to national criminal law are not a particularly helpful tool for interpreting Article 4 and determining its severity threshold.

Finally, the Grand Chamber made it explicit that both national and transnational human trafficking fall within the definitional limits of Article 4. This is in accordance with the approach under Article 2 of the CoE Trafficking Convention. It has not been, however, appreciated that the inclusion of human trafficking that takes places exclusively within national borders, raises some difficult conceptual issues (Stoyanova, Human Trafficking and Slavery Reconsidered page 41). One of them is the conflating with other national offences (e.g. fraud, coercion, deception, abduction, pimping and procurement). One remains to wonder whether it is now possible to review all of them under the terms of Article 4 ECHR. If yes, this risks undermining the distinctive value of this provision.

Prostitution and Article 4

The definition of human trafficking as stipulated by the Palermo Protocol and the CoE Trafficking Convention, includes ‘sexual exploitation’ and ‘the exploitation of the prostitution of others’ as possible purposes of human trafficking. As the Grand Chamber correctly noted in S.M. v Croatia, this inclusion ‘opens up some very sensitive issues relating to the approach to prostitution in general.’ (para 298) As para 88 of the Explanatory Report to the CoE Trafficking Convention says ‘[t]he terms “exploitation of the prostitution of others” and “other forms of sexual exploitation” are not defined in the Convention, which is therefore without prejudice to how States Parties deal with prostitution in domestic law.’ This means that these sensitive issues are to be resolved at national level, where different approaches have been adopted in different CoE states.

When it comes to ECHR level and its Article 4, the Grand Chamber clarified that

the notion of “forced or compulsory labour” under Article 4 of the Convention aims to protect against instances of serious exploitation, such as forced prostitution, irrespective of whether, in the particular circumstances of a case, they are related to the specific human trafficking context. Moreover, any such conduct may have elements qualifying it as “servitude” or “slavery” under Article 4, or may raise an issue under another provision of the Convention. (para 300)

It follows that only forced prostitution can fall within the definitional parameters of Article 4. Forced prostitution might be included within these parameters regardless of whether it is one of the purposes of human trafficking, whether it can be classified as forced labour or whether it might also meet the severity thresholds of slavery or servitude.

One of the challenges here concerns the meaning of ‘force’. The analysis in S.M. v Croatia does not include a determination whether S.M. was actually forced into prostitution. The judgment was limited to the finding that the national authorities did not make sufficient efforts to  themselves make an assessment whether S.M. was forced. The Grand Chamber did add, however, that ‘it is important to stress that “force” may encompass the subtle forms of coercive conduct identified in the Court’s case law on Article 4, as well as by the ILO and in other international materials. (para 301)’


The Grand Chamber in S.M. v Croatia tried to resolve some of the conceptual confusions sowed with Rantsev v Cyprus and Russia. To some extent, this was successful. In particular, the clarification that only ‘forced prostitution’ is covered by Article 4, can be assessed as useful. Other issues, however, have remained open, such as the relationship between the concept of human trafficking, on the one hand, and the concepts explicitly included in Article 4 (slavery, servitude and forced labour).

One thought on “The Grand Chamber Judgment in S.M. v Croatia: Human Trafficking, Prostitution and the Definitional Scope of Article 4 ECHR

  1. Important post and ruling. Worth to note, the separate opinion of judge Serghides, who takes a “direct methodological approach” to that issue, in order to give effectiveness to the meaning of article 4 (2) to the convention.

    What he claims, is that, I quote:

    “Forced or compulsory labour” may occur in many different contexts and is not limited to “human trafficking” and/or “exploitation of prostitution. The very nature of the appalling exploitation of human beings involved in “human trafficking” and/or “exploitation of prostitution” is such that it must automatically fall within the scope of Article 4 § 2.”

    So, it is even illustrated by the article itself, negating or excluding, several forms of kind of compulsory labour ( like serving in the army). In that method, using the terminology of : ” intension and extension” he uses linguistic as useful tool for analyzing the legal text. There are generic words ( like “ship” brought by him) and all sorts of ships on the other hand, I quote:

    “In logic, the intension (otherwise: connotation, comprehension, definition or depth), consists of the essential qualities, properties or characteristics of a term, and extension (otherwise: denotation, classification or breadth) consists of the matters or instances to which the term refers. An easy distinction between the two can be illustrated through the example of the term “ship”. The intension of this term would be a “vehicle for conveyance on water”, whereas its extension would embrace cargo ships, passenger ships, battleships, and sailing ships.”

    So, the same relationship, between human trafficking and forced labour, should be implied here. ( trafficking as extension suppose, of forced labour).

    Another way to look at it, is to unify in serious crimes of such, between the main offense, and derivative offenses. Trafficking, is sort of derivative offense, of forced labour. For, it does facilitate the offense itself. Like being: accessory, abetting and aiding, or, conspiracy at first place etc….. In many judiciaries, when one offense is considered serious and grave, conspiracy is like committing the offense itself.


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