This article is concerned with explaining why peace endures in countries that have experienced a civil armed conflict. We use a mixed methods approach by evaluating six case studies (Burundi, East Timor, El Salvador, Liberia, Nepal, Sierra Leone) and survival analysis that allows us to consider 205 peace episodes since 1990. We find that it is difficult to explain why peace endures using statistical analysis but there is some indication that conflict termination is important in post-conflict stabilisation: negotiated settlements are more likely to break down than military victories. We also consider the impact of UN peacekeeping operations on the duration of peace but find little evidence of their contribution. However, in situations where UN peacekeeping operations are deployed in support of negotiated settlements they do seem to contribute to peace stabilisation.

The article aims to examine, in light of the codification work of the International Law Commission and of the most recent practice, some issues concerning the allocation of responsibility between an organisation and its troop-contributing states for the conduct taken in the course of a multinational operation (with a specific focus on UN operations). After explaining the general rule of attribution of conduct based on the status of the multinational force as an organ or an agent of the organisation, this article will examine the validity of special rules of attribution of conduct based on the notions of ‘effective control’ or ‘ultimate control’ over the acts of the multinational force. Finally, I will discuss the possibility of dual responsibility of both the organisation and the troop-contributing state concerned.