Irredentism developed into an anomaly in post-World War II Europe and — contradicting the dire predictions of the 1990s — has remained an anomaly even since the end of the Cold War. Focusing on the renunciation of the FRG’s and the Republic of Ireland’s irredentist claims, I propose a novel route to analyse dispute settlement. I contend that nations justify their stance in a conflict. In the case of irredentism, they do not merely assert that a disputed territory is their land but justify to themselves and others why the disputed territory is rightfully theirs and why pursuing the irredentist stance is worthwhile. The disruption of this justification — what I call dejustification — constitutes a pathway to dispute settlement. Dejustification occurs through a change of the ideational environment that serves as the resource for justifying the claim and an advocacy that constructs a mismatch between environment and claim.