Is there a right of humanitarian intervention? Can a state legitimately intervene, if necessary, by military means, in the affairs of another state for humanitarian purposes? For most, if not all, of the last century there has been no international consensus that such a right exists in international law. In this chapter I shall argue that – where human rights are seriously under threat – there is a moral right to intervene for humanitarian purposes, and that there should be a corresponding legal right. International law should be amended, as required, to reflect the moral consensus that is emerging in the twenty-first century in favour of intervention. This question raises profound issues of philosophy, theology, jurisprudence and politics. But it is also an intensely practical moral issue.

The moral challenge of Rwanda

In April 2004 world leaders commemorated the tenth anniversary of what happened in Rwanda when the international community failed to agree on humanitarian intervention. The cost of that failure had been high. Following the shooting down of a plane carrying the presidents of Rwanda and Burundi on 6 April 1994, the Hutu-dominated Rwandan military unleashed a genocidal assault on the minority Tutsis. This led to the deaths of over 800,000 Tutsis. The United Nations, which had a small military presence in Rwanda and was well aware of what was happening, did nothing.