Abstract:This paper explores the international implications of liberal theories which extend justice to sentient animals. In particular, it asks whether they imply that coercive military intervention in a state by external agents to prevent, halt or minimise violations of basic animal rights ('humane intervention') can be justified. In so doing, it employs Simon Caney's theory of humanitarian intervention and applies it to non-human animals. It argues that while humane intervention can be justified in principle, using Caney's assumptions, justifying any particular intervention on behalf of animals is much more difficult -and in present circumstances impossible. If these claims are correct, a number of important conclusions follow. First, all states lack legitimacy because of the horrors that they inflict upon animals. As a result of this, all states are thus prima facie liable to intervention by external agents. To remedy this situation, all states have the responsibility to massively transform their relationship with non-human animals, and to build international institutions to oversee the proper protection of their most basic rights.