The Islamic State of Iraq and Syria is considered one of the most serious threats to the entire world. In order to provide a lawful response against this threat, it is necessary to verify whether the Islamic State is actually a State. The concept of State is still at the centre of the contemporary international legal order, but there is not a general consensus about the elements that constitute a State under international law, and the conditions pursuant to which international personality is conferred to an entity claiming statehood. Accordingly, it can be useful to examine both the factual bases of the Islamic State and its legal entitlement to aspire to become an independent State under international law. From this enquiry, at the moment the Islamic State appears not to be a State in light of international law, but rather a group of insurgents with a territorial basis.