Following the attacks of 11 September, a major question that has arisen within the international community is the effi ciency of the existing anti-terrorism legal regime. Notwithstanding the enactment, since the 1970s, of a series of conventions2 aimed at addressing this crime, these have proven to be less effective than expected. Partly the reason has been their focus on sub-forms of terrorism, rather than the phenomenon in its complexity, thus failing to cover its more modern manifestations. At the same time, the widespread belief that terrorism is a subjective notion, dependent on an individual’s political beliefs – from which the motto ‘one man’s terrorist is another man’s freedom fi ghter’ derives – has made it impossible to achieve universal consensus on a comprehensive anti-terrorism convention. Another reason is that the enforcement of the existing instruments very much depends on the political willingness of the State Parties to support the international cooperation in criminal matters. Often the exceptions provided under extradition law, such as the clause that a State cannot be compelled to extradite its own citizens – as occurred in the Lockerbie Case3 – or the political offence exception, have allowed terrorists to fi nd safe havens. The aim of this chapter is to study an alternative way, namely that of trying to prosecute terrorism, as understood in the common language – that is, as a violent act aimed at raising fear within the population, in order to force a government or a community to meet the political demands of the perpetrators – as a crime against humanity under Article 7 of the Rome Statute for an International Criminal Court (ICC).