This article will consider the ways in which the role of humanitarian intervention, which currently does not have any clear legal status, can be defended through international law. Using both realist and liberal cosmopolitan theoretical approaches, it will consider three notions of legitimacy to argue that humanitarian intervention can be justified – that is: Legitimacy through humanitarian crises; humanitarian intervention supported through a creative interpretation and application of general principles of international law; and humanitarian intervention justified by morality and “natural law.” It will consider the use of force that has taken place in Iraq, Afghanistan and Libya as case-studies and examples. A broader sense of legality wil...