This theoretical paper contrasts "new" (non-state) armed conflicts with conventional (state-based) armed conflicts. While the former are fought between entirely non-state or sub-state actors (e.g. between warlords) the latter involve government forces fighting one or several internal opposition groups (e.g. conventional greed or grievance rebellions). The first part of this paper aims to identify why individuals participate in either sub-type of internal armed conflict. For this purpose, I rely on the Deprived Actor Model, the Rational Actor Model and the concept of New Wars. Secondly, I ask in how far differences in the nature of involved actors can be linked with differences in the intensity and duration of fighting. While the first part of this paper focuses on the causes and individuals´ motivation for the outbreak of internal warfare, this second part aims to explain the nature of non-state warfare and to identify the mechanisms linking its dimensions. More specifically, I ask whether a privatization of actors comes along with a fractionalization and trans-nationalization of actors, an economization of motives, a brutalization of strategies, and more extensive fighting.
