An earthquake. A conflict. A tsunami. A coup. Increasingly, non-international armed conflicts send thousands of civilians fleeing across borders to safety, whilst (natural) disasters hit areas of the world where resources to address the calamity are scarce. Coinciding emergencies or deliberate obstruction by authorities exacerbate the already dire situation. A humanitarian crisis often ensues. The result of these crises is an immediate and large-scale need for food, water, shelter and medicine: in other words, the provision of humanitarian assistance. Whereas the need for such assistance may...