Humanitarian intervention is a staple of current discussions about relations among states. Should powerful states interfere in the internal affairs of weaker ones, particularly those identified as failed states, in order to bring peace and stability when it is clear that the existing government can not do so? The concept is an old one, not a new one. European nations that engaged in overseas expansion generally justified their conquests on the grounds that they would seek to civilise and Christianise the (...) peoples whom they encountered. The most extensive discussion of the right ? or the responsibility ? of strong states to intervene on a humanitarian basis occurred among sixteenth- and seventeenth-century Spanish intellectuals who sought to justify the Spanish conquest of the Americas. The most famous of these figures was Francisco de Vitoria (1485?1546) whose De Indis outlined all of the arguments that could be raised for and against such intervention. His line of argument suggests that in the long run, intervention even with the best of intentions, may well lead to tragic consequences. It may even be hubris, the sin of those who would play God. (shrink)