This paper examines the notion of intensity in the context of common Article 3 and Additional Protocol II (AP II) to the Geneva Conventions in order to establish whether AP II demands a different intensity threshold from the minimum threshold of intensity contemplated in common Article 3. The paper considers the question of whether the inclusion of the term “sustained” in the phrase “sustained and concerted military operations” intrinsic to the threshold in Article 1(1) of AP II introduces a temporal requirement in addition to mere protracted armed violence. The paper argues that the inclusion of the term “sustained” in Article 1(1) of AP II potentially demands prolonged protracted armed violence. The research aims to contribute to the existing literature on the notion of intensity demanded by the scope of application inherent in AP II through an interrogation of the phrase “sustained” military operations by employing the rules of treaty interpretation and by examining relevant case law and scholarly debate. In this way, the author hopes to contribute towards filling a lacuna with regard to the minimum threshold for intensity in the context of treaty law concerned with the classification of non-international armed conflicts.