Necessity and Proportionality and Armed Attacks by Non-State Actors

Abstract

Chapter 4 builds on the analysis of the previous chapters by considering how necessity and proportionality are adapted to apply to defensive action against NSAs. With a particular focus on international terrorism, including the ongoing Global Coalition intervention in Syria against Daesh and other terrorist groups, the potential and limitations of necessity and proportionality are brought to the fore. In particular, this chapter examines the position of the ‘host state’ (being the state in whose territory military action is taken), which includes a review of the controversial ‘unwilling or unable’ doctrine. The duration and geographical scope of the right of self-defence are also considered in this context. A worrying trend is identified regarding how states appear to take a more permissive attitude towards anti-terrorist operations. This state practice has serious implications for the meaningful application of proportionality, whilst highlighting the potential for specific necessity to act as a restraint on state action.