M.C. v. BULGARIA JUDGMENT 29 155. The limits of the national authorities' margin of appreciation are nonetheless circumscribed by the Convention provisions. In interpreting them, since the Convention is first and foremost a system for the protection of human rights, the Court must have regard to the changing conditions within Contracting States and respond, for example, to any evolving convergence as to the standards to be achieved (see Christine Goodwin v. the United Kingdom [GC], no. 28957/95, § 74, ECHR 2002-VI). 156. The Court observes that, historically, proof of physical force and physical resistance was required under domestic law and practice in rape cases in a number of countries. The last decades, however, have seen a clear and steady trend in Europe and some other parts of the world towards abandoning formalistic definitions and narrow interpretations of the law in this area (see paragraphs 88-108 and 126-47 above). 157. Firstly, it appears that a requirement that the victim must resist physically is no longer present in the statutes of European countries. 158. In common-law countries, in Europe and elsewhere, reference to physical force has been removed from the legislation and/or case-law (see paragraphs 98, 100 and 138-47 above, in relation to Ireland, the United Kingdom, the United States of America and other countries). Irish law explicitly states that consent cannot be inferred from lack of resistance (see paragraph 98 above). 159. In most European countries influenced by the continental legal tradition, the definition of rape contains references to the use of violence or threats of violence by the perpetrator. It is significant, however, that in case-law and legal theory lack of consent, not force, is seen as the constituent element of the offence of rape (see paragraphs 90-97, 99 and 130-37 above). 160. Belgian law was amended in 1989 to state that any act of sexual penetration would constitute rape when committed in respect of a person who had not given consent. Thus, while the reference to “violence, duress or ruse” as punishable means of imposing a non-consensual act remains in the statute, violence and/or physical resistance are not elements of rape in Belgian law (see paragraphs 90 and 130-34 above). 161. Regardless of the specific wording chosen by the legislature, in a number of countries the prosecution of non-consensual sexual acts in all circumstances is sought in practice by means of interpretation of the relevant statutory terms (“coercion”, “violence”, “duress”, “threat”, “ruse”, “surprise” or others) and through a context-sensitive assessment of the evidence (see paragraphs 95 and 130-47 above). 162. The Court also notes that the member States of the Council of Europe, through the Committee of Ministers, have agreed that penalising non-consensual sexual acts, “[including] in cases where the victim does not show signs of resistance”, is necessary for the effective protection of women