The article discusses the regional integration of the Asia-Pacific, an area comprising 1/3 of the surface of the globe. Spanning three continents (America, Asia and Oceania), the area is composed by a variety of territories, which are both sovereign and nonsovereign states, characterised by different traditions, historical background, economic development and constitutional arrangements. This peculiar situation affects significantly the regional integration process, which is particularly fragmented in the Pacific. Furthermore, the regional organisations are all intergovernmental organisations, whose decision-making process follows the method of consensus and favours soft law instruments. Hence, the normative production in these organisations is almost inexistent. Tradition as meta-formant, rather than legal formants, play a major role in the context of ASEAN, in the form of both an ASEAN identity and a specific ideology against the universalism of human rights. On the contrary, in the South Pacific, in the context of the Commonwealth, legal formants are more relevant, mainly in the form of the common law; nonetheless, this is mainly due to the colonial past rather than to the normative power of the Commonwealth as an international organisation. However, it is still interesting to analyse the interplay of the common law and the tradition in the hierarchy of sources, mainly to assess whether it can trigger a stronger regional integration.