tomed to exercising jurisdiction solely on the basis of territoriality, it is required to extend its jurisdiction over persons holding its nationality.122 When the victim is a national of the State, the State may establish its jurisdiction over the crime if, in view of the wording of the Convention, the State deems this to be appropriate. It follows from the wording that this is merely a discretionary option and not an obligation. § 2. Article 5 §2 forms a foundation stone for universal reaction to torture under criminal law.123 The provision imposes an obligation on each State Party to establish jurisdiction in its domestic legislation over any alleged torturer who is found within its territory and who is not extradited pursuant to Article 8 or to any of the States listed in Article 5 §1. It should be noted that the provision does not prescribe the establishment of universal jurisdiction in absentia, meaning that States are not obliged under the Convention to extend their jurisdiction over cases not falling under Article 5 §1 to cover cases where the alleged offender is not present in their territory. It also follows that if the offender is not present in such territory, the States are under no obligation to establish jurisdiction upon which a request for extradition could be based.124 II. INDIVIDUAL ANALYSIS OF ARTICLES 1–16 OF THE CONVENTION 2. ANALYSIS OF SUBSTANTIVE PROVISIONS The decision to include universal jurisdiction in the Convention over persons accused of torture was linked to the nature of torture as defined in Article 1 of the Convention. With the involvement of the State being a necessary element of torture, few successful prosecutions of torture offenders before national courts can be expected. The Convention therefore offers other States Parties a basis for filling the gaps left by States which do not act against torture.125 38 The involvement of a State in torture was also thought to justify the breach of its sovereignty by other States engaging in criminal prosecution of the offending State’s nationals. Article 5 §2 is an independent basis for jurisdiction which may be invoked regardless of whether another basis of jurisdiction exists. According to recognised authorities on the subject: “Paragraph 2 [of Article 5] provides that, whether or not any of the grounds of jurisdiction dealt with in paragraph 1 exist, a State Party shall have jurisdiction over offences of torture in all cases where the alleged offender is present in a territory under its jurisdiction and it does not extradite him to a State which has jurisdiction under paragraph 1.”126 The term “any territory under its jurisdiction” should be read broadly. It applies to alleged offenders present in any “territories over which a State has factual control”.127 The phrase “take such measures as may be necessary to establish its jurisdiction in cases where the alleged offender is present” includes legislative measures,