In recent years, a burgeoning literature has explored the strategic advantages of using nonviolent resistance to achieve positive political outcomes, such as regime change and democratization. Yet, despite one-fifth of largescale nonviolent campaigns occurring during the course of a civil war, we know little about the effect nonviolent resistance might have on the transformation of armed conflict. Bringing together the previously isolated literatures on nonviolent resistance and peacebuilding, this monograph explores how nonviolent resistance can aid peacebuilding efforts that transform ongoing armed conflict, using data on all civil wars episodes since 1945. The findings show nonviolent resistance does have a positive impact on the resolution of armed conflict and post-conflict democratization, with evidence deriving from a Large-N statistical analysis, out-of-sample prediction, and structured-focused case studies.