Making up is hard to do: reconciliation after interstate war

The issue of rapprochement between former adversaries has received scant scholarly attention meaning there is little understanding of why some foes reconcile quickly, while others remain hostile for decades. Moreover, a specific facet of reconciliation, diplomatic normalization, while a crucial part of diplomacy, has not been explained by scholarly work. This study advances research on diplomatic normalization while proposing a novel theory of reconciliation involving Kantian elements: commerce, democracy, and law. Specifically, the paper proposes that significant economic incentives generate domestic lobbies in favour of normalization, while democratic norms and international institutions generate trust and transparency. This theory is tested on a new dataset that includes all potential cases of reconciliation after warfare since World War II. Survival analysis shows that market size, shared democracy, and joint international organization membership are significantly related to faster reconciliation. The causal mechanisms are examined in a case study of US—Vietnamese rapprochement. The policy implications for these findings and the limitations for political leaders are also discussed.