This chapter focuses on four broad scenarios through which tensions in the sea might inform and influence the future development of Southeast Asian relations and the emerging regional order. They are nobody's sea: stable cohabitation; somebody's sea: regional hegemony; everybody's sea: managed mistrust; and sea of conflict. The US has an important role to play as a key restraining influence in the South China Sea. Where US leadership has appeared weak or wanting – perhaps distracted by events elsewhere – the unintentional result has been the indirect encouragement of greater Chinese assertiveness. Ultimately leaders in China, Southeast Asia and the US will change, militaries will evolve and populism will rise and fall. Yet the underlying strategic geography of the South China Sea will remain. US, Chinese and Southeast Asian interests would all be served by a contextualisation of South China Sea's disputes outside of the framework of a rising China and the reactions of the US as the established hegemon.