CONCURRING OPINION OF JUDGE KELLER

1. I voted with the majority for a finding of a violation of Articles 8 and 14 of the Convention. A difference in treatment of widows and widowers as exemplified in the present case is no longer justifiable today. Furthermore, the application of Article 8 in the instant case is necessitated by a number of recent judgments (see paragraphs 38-40 of the Chamber judgment). However, I find the reasoning set out by the Court difficult to follow for several reasons. Indeed, in my view such case-law is based on a truncated interpretation of Article 8 and is incompatible with the teachings of treaty law and the Grand Chamber. The path chosen by the Court amounts to imposing on the respondent State commitments into which it deliberately declined to enter in deciding not to ratify Protocol No. 1 to the Convention.

2. First of all, for the same reasons as I set out together with Judges Spano and Kjølbro in the case of Di Trizio v. Switzerland (no. 7186/09, 2 February 2016), and with Judge Dedov in Belli and Arquier-Martinez v. Switzerland (no. 65550/13, 11 December 2018), I consider that the complaint put forward in the present case is primarily of a pecuniary nature and that it falls within the ambit of Article 1 of Protocol No. 1 rather than Article 8 of the Convention.

3. Indeed, there can be no doubt in the present case that the applicant’s complaint concerned the payment of a social welfare benefit. The relevant case-law is clear as regards the fact that such benefits usually fall under Article 1 of Protocol No. 1 (see, for an outline of the principles governing this subject matter, Bélané Nagy v. Hungary [GC] , no. 53080/13, §§ 80-89, 13 December 2016). Indeed, “(i)f ... a Contracting State has in force legislation providing for the payment as of right of a welfare benefit – whether conditional or not on the prior payment of contributions – that legislation must be regarded as generating a proprietary interest falling within the ambit of Article 1 of Protocol No. 1 for persons satisfying its requirements” ( see Stec and Others v. the United Kingdom (dec.) [GC], nos. 65731/01 and 65900/01, § 54, ECHR 2005 ‑ X). More specifically, the Court has confirmed that disputes concerning payment of a survivor’s pension fall within the ambit of that provision (see Åžerife YiÄŸit v. Turkey [GC], no. 3976/05, §§ 57-59, 2 November 2010).

4. Nor is there any doubt that the Convention and its Protocols must be read as a whole (see, for example, Osmanoğlu and Kocabaş v. Switzerland , no. 29086/12, § 90, 10 January 2017). Nevertheless, that requirement does not mean that Article 8 of the Convention must be understood as encompassing all the obligations flowing from Article 1 of Protocol No. 1. There are at least two reasons for that.

5. Firstly, one of the fundamental principles of treaty law is that treaties must be interpreted on the basis of the common intention of the parties (see Dispute regarding navigational and related rights (Costa Rica v. Nicaragua), judgment, I.C.J. Reports 2009, § 63). In that connection, the adoption by the parties to a treaty of a protocol concerning specific subjects obviously manifests their joint intention that the latter should not be governed by the original treaty (cf. Magyar Helsinki Bizottság v. Hungary [GC], no. 18030/11, §§ 51 and 136, 8 November 2016).

6. Moreover, as the Grand Chamber stated in connection with Article 2 of Protocol No. 4, “Article 5 should not, in principle, be interpreted in such a way as to incorporate the requirements of Protocol No. 4 in respect of States which have not ratified it, including the United Kingdom” (see Austin and Others v. the United Kingdom [GC] , no. 39692/09 and 2 others, § 55, ECHR 2012). [1] Therefore, the Protocols are not systematically taken into account in interpreting provisions of the Convention; far from it.

7. This divergence of approaches adopted by the Court is regrettable in terms of the legitimacy of the Convention system. In the present case, by extending the criterion for the applicability of Article 8, the Court is once more taking on a role comparable to that of a “Supreme Social Insurance Court” with regard to a State which has deliberately not accepted such a situation.

8. The foregoing considerations show the ramifications of an issue which extend far beyond Switzerland and Protocol No. 1 to raise the more general question of the place of the Protocols in the interpretation of the Convention. In my view the Grand Chamber must be called upon to settle this vital issue.

[1] Conversely, it is logical to interpret the Protocols in the light of the Convention, which is by definition ratified by all the High Contracting Parties (see, for example, Burghartz v. Switzerland , 22 February 1994, §§ 23-24, Series A no. 280 ‑ B, and Enver Åžahin v. Turkey , no. 23065/12, § 59, 30 January 2018).