When faced with an external humanitarian crisis, the European Union Member States have three intervention alternatives; they can decide to intervene independently from the EU (unilateral intervention), to delegate the intervention to the EU institutions (full delegation to the EU), or to intervene in collaboration with them (partial delegation to the EU). This paper analyses the choice of the intervention strategy with reference to the specific crisis context the Member States have to cope with. Adopting a rationalist approach, this paper indeed claims that the characteristics of the humanitarian crisis may influence Member States’ intervention strategies. Accordingly, humanitarian crises are supposed to be characterised, to a different extent, by urgency, uncertainty and threat. Urgency refers to the time pressure faced by Member States in order to rapidly react to a humanitarian crisis. Uncertainty concerns the information at their disposal to effectively plan the intervention. Threat refers to the nature (including both man-made and natural disasters), diffusion and seriousness of a crisis. Such characteristics are expected to impact on the expediency of the three intervention alternatives, and, as a consequence, influence Member States’ choices. With the aim of discussing and testing this claim, this paper first illustrates crisis characteristics in regard to their possible impact on the costs and benefits of a bilateral and multilateral intervention. Then, it investigates how changes in crisis characteristics may entail changes in the expediency of intervention alternatives. Finally, it formulates more precise hypotheses about the direction and effect of this impact. With a quantitative statistical approach, the following hypotheses are formulated:
1. the inclination towards any form of delegation, instead of unilateralism, increases when the crisis is highly urgent, uncertainty and threat;
2. the inclination towards full delegation, instead of partial delegation, increases when the crisis is highly urgent, uncertainty and threat.
