right that no-one shall be held guilty of a criminal offence that did not constitute a crime at the time it was committed (no punishment without law).106 Furthermore, the right must be interpreted “in such a way as to provide effective safeguards against arbitrary prosecution, conviction and punishment.”107 As an offshoot of this principle, criminal law should be strictly applied and restrictively interpreted; it should not be interpreted by analogy, and any ambiguity should be resolved in favour of the accused.108 Legislation criminalizing FTF-related conduct, and its interpretation and application in practice, clashes with these fundamental principles. Crimes, inchoate offences and modes of liability that target not only travel for some ill-defined purpose, but also other forms of support, such as funding or facilitating travel; “indirectly inciting”, “expressing appreciation of”, “justifying”, “provoking” or “apologizing for” terrorism or “disseminating messages” in relation to FTF activities are extremely expansive in their potential scope of application, and are ridden with ambiguity. In addition, broad interpretations of existing laws regarding what constitutes “incitement” raise serious questions concerning the strict interpretation of criminal law. The imposition of obligations on states in UNSC Resolution 2178 (2014) to establish criminal offences for a broad range of conduct in relation to FTFs, without clearly identifying the basic mental and material elements (or the criminal intent and conduct), has been much criticized.109 Problems associated with the lack of a clear definition of terrorism are compounded by the inherent breadth and ambiguity of terms used to describe FTF-related conduct. However, while Resolution 2178 (2014) provides the framework of obligations, it falls to states to give them effect in criminal law in a manner that respects the principle of legality and clarifies the scope of criminality. The burden, therefore, falls on individual states to ensure that their national legislation clearly and specifically defines the material and mental elements of FTF-related crimes. Criminal Responsibility and Individual Culpability It is an essential principle of criminal law, reflected in international law, that responsibility must be individual, not collective.110 The most basic principle of criminal law is that 106  Article 4 ICCPR, Article 15 ECHR and Article 27 ACHR all expressly proscribe derogation from this right. 107 See: S.W. v. United Kingdom and C.R. v. United Kingdom, ECtHR, Judgments of 22 November 1995, cited in Streletz, Kessler and Krenz v. Germany, Judgment of 22 March 2001, para. 50. The passage continues: “It should be construed and applied, as follows from its object and purpose, in such a way as to provide effective safeguards against arbitrary prosecution, conviction and punishment.” 108  See e.g., “European Parliament resolution of 22 May 2012 on an EU approach to criminal law (2010/2310(INI))”, European Parliament, P7_TA(2012)0208, <https://eur-lex.europa.eu/legal-content/EN/ TXT/?uri=celex:52012IP0208> (hereafter, European Parliament, EU Approach to Criminal Law). 109  M. Scheinin, “Back to post-9/11” op. cit., note 51. 110 ICTY, Prosecutor v. Tadic, (Case No. IT-94-1-A), Judgment (Appeals Chamber), 15 July 1999, para. 186: “nobody may be held criminally responsible for acts in which he has not personally engaged or in some way participated”. On the prohibition on collective punishments in international humanitarian law, see Article 33 of the 1949 Geneva Convention (IV) on Civilians; Article 75 of Additional Protocol I, Article 6(2) Additional Protocol II. 36 Guidelines for Addressing the Threats and Challenges of “Foreign Terrorist Fighters”