No-one is safe until everyone is safe. But what can be donewhen a country fails to take measures to control a pandemicvirus? It poses a threat to its own people but also to its neighbours and beyond. Countries do pool sovereignty, working through supra-national structures, such as international agencies, or using processes set out in treaties, recognising the mutual benefits of the international rules-based system. Here we review the ways in which governments have, or have not worked together on other issues that pose a threat to global health and discuss the implications for pandemic responses.