The rapid growth of international aid allocated to "complex humanitarian emergencies" has led to parallel calls for preventive action. It is also being asked how humanitarian assistance and other forms of international civilian presence can help prevent and mitigate violent conflict. The key question raised in the report is: What do we know about how, and why, humanitarian presence may help prevent or contain conflict? What are the conditions for failure or success? Can humanitarian presence have counterproductive effects and exacerbate conflict? How can unintended consequences be avoided? The report reviews the relationship between humanitarian assistance and violent conflict. It is basically a "state-of-the-art" review, supplemented with data drawn from some classic cases and interviews with Norwegian NGOs.