How do apologies and other acts of contrition after war and atrocities matter in international politics? Much of the existing scholarship has been concerned with whether such gestures can facilitate reconciliation between perpetrators and victims. While recognizing the value of such scholarship, this entry also discusses what apologies and other acts of contrition do more broadly. It suggests that apologies can have effects other than facilitating reconciliation. Apologies and other acts of contrition provide opportunities for former perpetrators to distinguish themselves from what they used to be. Through such differentiation, states and collectives that transgressed in the past can construct new identities for themselves and relate in new ways to other states and groups. However, this entry also suggests other possible consequences of such identity redefinition through apologies. First, it may lead the former transgressor to want this new self-understanding to be recognized by others. If such recognition is not forthcoming, it might result in bilateral friction. Second, such changes may also contribute to enabling security policies that previously could not be enacted. These points are developed and illustrated through engagement with the case of Japanese apologies for colonialism and World War II.