Wallis, Joanne2016-08-292016-08-291466-2043http://hdl.handle.net/1885/107333How can fragmented or divided post-conflict societies best be accommodated and adjust to state structures in order to achieve sustainable peace? Reflecting on the contrary experiences of Timor-Leste and Bougainville, an autonomous region of Papua New Guinea, this article argues the answer to this question rests partly on the role that participatory constitution-making can play in state-building, nation-building and peace-building. Constitution-making can play a central role in state-building, because constitutions provide the operating system that establishes state institutions and regulates state power. It can also play a nation-building role by defining the political bond between the people, and a peace-building role by encouraging reconciliation and embedding state institutions in society. This article draws on liberal political theory to argue that public participation in constitution-making can enhance the likelihood that the constitution produces legitimate and effective state institutions, generates a unifying sense of national identity and establishes sustainable peace. It finds that extensive public participation in Bougainville played a positive role by creating a sense of common identity, reconciling many of the most severe societal divisions and creating institutions that are relatively legitimate and effective. In contrast, minimal public participation in Timor-Leste meant that the constitution-making process did not play a positive role; it did not create a unifying national identity, left certain societal divisions unreconciled and exacerbated others, and created institutions that were largely illegitimate and ineffective.I gratefully acknowledge the financial support of the Research School of Asia and Pacific and the Strategic and Defence Studies Centre.25 pages© Taylor & Francis (Routledge)constitution-makingpublic participationstate-buildingTimor-LesteBougainville201610.1080/14662043.2016.1185245