This article investigates whether the South China Sea is a source of internal disagreement or unity in ASEAN. It argues that when the focus is on the possibilities of cooperation beyond what is necessary for regional peace and stability, five different member-state groupings can be identified according to their outlook on the desirable level of US and Chinese regional engagement, their support for a dialogue focusing on Sino-Southeast Asian cooperation and their views on the scope of a code of conduct. By contrast, when addressing the prospects of coexistence, unity prevails within ASEAN. The memberstates are in agreement that Southeast Asia cannot opt out of the structure of deterrence that is consolidated between the USA and China. In addition, they agree that a practice of consultation and a conservative code of conduct between Southeast Asia and China will contribute to peace and stability by offering assurance that pending disputes in the South China Sea will be settled by the indigenous powers through peaceful means and will remain separate from the outer structure of strategic competition.