This article investigates and defines the essential variables in the historical peace processes in Northern Ireland and Korea and sets essential preconditions for future peace negotiations on the Korean Peninsula. To do so, we conduct a rigorous examination of all Northern Irish agreements to indicate why past Korean peace processes have failed and to offer alternative policy suggestions. Crucial ingredients for a successful peace process are the structure of each negotiation framework, the inclusion of and concessions by key actors in each negotiation, the respect of core interests of each party, and tangible reduction of tensions.