This chapter discusses the classification of armed conflcits into international armed conflicts (IACs) and non-international armed conflicts ( NIACs) by examining the relevant criteria. WIth regard to NIACs it disusses the criteria of organisation and intensity. The chapter also considers the geographical and temporal scope of armed conflicts. It then goes on to consider occupation, wars of self-determination, terrorism and cyber war, as well the character of conflicts when international forces are involved.

International humanitarian law (‘IHL’), also known as the law of armed conflict (‘LOAC’), is a branch of international law that regulates the behaviour of participants in armed conflicts and encompasses rules on the military targeting of persons and objects, the means and methods of warfare, the protection of persons and objects, and the implementation and enforcement of the law. International humanitarian law is also one of the most highly codified fields of international law, with numerous treaties adopted over the last 150 years; many of these have also attained customary status. In developing IHL, states have recognised that, while the ultimate aim of society should be to strive to prevent war, wars will nonetheless occur, and that while ‘war will always constitute suffering and personal tragedy … rules of warfare are intended to prevent unnecessary suffering that yields little or no military advantage’. This balance between humanitarian aims and military objectives serves as the basic underpinning of all the modern laws of armed conflict.