Just as the Northern Ireland and Israeli-Palestinian peace processes appeared close to achieving lasting resolutions to conflict, both initiatives fell into crisis. This study combines power conflict and transaction cost approaches to analyze the strengths and the weaknesses of the Belfast Good Friday (BGF) and the Oslo peace processes. Dimensions that empower participants and increase certainty strengthen peace processes. Dimensions that are disempowering of participants and decrease certainty weaken peace processes. The two peace processes shared the strengths of including militant nationalists in negotiations and generating international pressure and support. Unlike the Oslo process, the BGF process benefited from greater constitutional certainty, minority safeguards, grass-roots legitimacy, effective responses to spoilers, and minority-supportive intervention by the US government. Unlike the BGF process, the Oslo process benefited from broad international participation in negotiations, leading to agreements that had clearly specified mechanisms for implementation. Shared weaknesses of the two processes included transgressing zero-sum game assumptions and identity boundaries, manipulation of popular fears by elites, and the marginal, if not negative, role played by civil society. In addition to pointing out ways that each peace process could benefit by appropriating the advantages of the other, the article offers several promising strategies for overcoming shared weaknesses, including challenging zero-sum assumptions, constructing more inclusive collective identities, grass-roots education regarding manipulative elites, strengthening non-sectarian segments of civil society, and breaking cycles of violence through reconciliation processes.