As it has been demonstrated, it is possible for serious acts of terrorism to be prosecuted as international crimes sourced in both the universal instruments against terrorism, other crime-related international instruments, as well as in customary international law.
In order to secure a possible conviction, however, it is necessary to find an appropriate forum in which suspected terrorists may be effectively and appropriately investigated, prosecuted, and, if convicted, sentenced. There can also be issues surrounding where such a person is to be imprisoned. Due to the complexities and serious nature of the terrorist crimes examined in this Module, it may well be more appropriate for them to be dealt with by an international court or tribunal, not only due to the wider interest of and impact upon the international community that such offences can have, but also because many national legal systems do not have the necessary expertise and resources to deal with such significant crimes. This was one of the original factors that led Trinidad and Tobago to seek the creation of the International Criminal Court, i.e., due to the complexity of transnational drug offences (see e.g. Bagoo, 2011).
Although they can be financially very costly and take a long time to get up and running, as demonstrated by the recent experiences of the International Criminal Court, international courts and tribunals have accompanying benefits as well. These can include the necessary technical and administrative expertise to manage sensitive and voluminous legal and political materials, and developing best practices, notably for securing justice and reparations for victims when national systems are unable to provide them with effective remedies.
That said, these courts and tribunals can encounter many of the same difficulties experienced by national courts, such as the reluctance or refusal even of States parties to the Rome Statute to disclose or hand over important evidence or suspects, despite their obligations under the treaty to cooperate fully with the International Criminal Court. That said, various mechanisms exist for dealing with such issues. For example, any citing of national security reasons as grounds for a refusal to cooperate are reviewable by Chambers and many result in negative inferences for the State concerned. Ultimately and exceptionally, in the most serious instances, compliance may be forced through legal means such as the adoption of a Chapter VII Security Council resolution (see e.g. UNSC Resolution 1207 (1998)).
Despite their serious nature and international interest in the effective, fair prosecution of serious international terrorist crimes, there are in fact very few international criminal courts or tribunals with jurisdiction over them, whether express or indirect. The only international tribunal with express jurisdiction over terrorism-related offences is the Special Tribunal for Lebanon (created by a Chapter VII Security Council Resolution, UNSC Resolution 1757 (2007)), which was specially created to investigate and prosecute one major terrorist incident and the jurisdiction of which is largely determined by Lebanese criminal law. In addition, several international courts and tribunals make some provision for terrorism related offences, notably the Statute of the International Criminal Tribunal for Rwanda (article 4(d)), the Statute of the Special Court for Sierra Leone (article 3(d)), and the Law on Establishment of the Extraordinary Chambers in the Courts of Cambodia (article 8). Regarding the former two tribunals, their jurisdiction is limited to those terrorist activities prohibited in international humanitarian law for temporal situations of specific armed conflicts.
Ultimately, the Rome Statute creating the ICC did not include terrorism offences within its jurisdiction despite multiple proposals by States for the inclusion of "treaty crimes" (United Nations conference 183/C.1/L.27, pp. 71-71), and lengthy related debates on the topic taking place during the treaty negotiations. Although the merits of including terrorist offences within the Court's remit were recognized, the Preparatory Committee was of the opinion that the Rome Statute should be restricted to defining the agreed international crimes within its jurisdiction. Other significant factors underpinning this decision included the lack of global agreement as to terrorism, various jurisdictional differences regarding the prosecution of terrorism-related crimes, and as highlighted above, issues concerning the universal instruments against terrorism are based on, and limited to, the principle of aut dedere aut judicare as previously explained. The other crimes falling with the Court's jurisdiction benefit from universal jurisdiction, which stands in stark contrast to the legal and political difficulties associated with the absence of a universal definition of terrorism, including the possibility of deterring a number of States from signing up to the treaty. The perception existed as well that terrorism, however defined, did not rank as one of the most serious crimes towards which the ICC should direct its scarce energy and resources. For such reasons, the Statute's jurisdiction is limited tothe crimes of genocide, crimes against humanity, war crimes and the crime of aggression (article 8bis) That said, the Assembly of States Parties to the Rome Statute agreed on 15 December 2017 to activate the jurisdiction of the Court over the crime of aggression, which will take effect from 17 July 2018. Such jurisdiction may be relevant for future counter-terrorism efforts involving military intervention. That said, to some extent some of these restrictions are overcome by the principle of complementarity (article 17).
It is at least theoretically and technically possible for the Rome Statute to be amended in the future to extend its jurisdiction to cover terrorism-related offences, although this is not expected to occur any time soon. The necessary treaty amendments would be accompanied by many complexities and hurdles, together with the likelihood of not quickly achieving the requisite levels of consensus, illustrated by the drawnout experience of almost 20 years to reach international agreement regarding the meaning and activation of the crime of aggression, which was originally included within the Statute's jurisdictional scope under article 5, subject to international agreement being reached, which has occurred. Furthermore, there are many other delicate political factors currently surrounding the International Criminal Court and its longer term future, including the recent withdrawals, and threats of withdrawal, from the Rome Statute by a number of States parties (see e.g. The Guardian (Addis Ababa), 2017). Most recently, Burundi announced its withdrawal (see Trahan, 2017).
In practice, however, such formal exclusion of terrorism-related offences from the express jurisdiction of most international courts and tribunals has not prevented international crimes of terrorism from being tried directly or indirectly in practice where their nature and gravity have satisfied the legal elements of those offences falling within the jurisdiction of these courts and tribunals. Certainly, as was discussed earlier, the international crimes of genocide, war crimes and crimes against humanity (see Rome Statute, arts. 6-8) can encompass a broad range of terrorist acts. Indeed, this is already the practice of international courts and tribunals, as is reflected within the jurisprudence of the International Criminal Tribunal for former Yugoslavia and the International Criminal Tribunal for Rwanda, Special Court for Sierra Leone and the International Criminal Court. There is a developing body of case law which supports such approaches, influenced by more general trends towards closing existing impunity gaps for non-State (terrorist) actors. (See e.g. Prosecutor v. Stanislav Gali ć, 2006, para. 598; Prosecutor v. Tihomir Blaškić, 2000). One benefit of this approach is that it does not require international agreement to be reached on a definition of terrorism, although this indirect approach does not perhaps attract the same degree of respect or have the gravitas as would express jurisdiction over terrorist crimes. Additionally, not all international terrorist crimes will comfortably fit within the legal elements of core international crimes, such as terrorist financing, particularly in view of the globalization of finance, as noted expressly in the 1999 Terrorism Financing Convention.