Irredentism and secessionism have been important causes of international conflict in the 1990s, yet few have considered why ethnic groups desire union with kin elsewhere or want to become independent. Why do groups desire independence rather than union with kin, or vice versa? We consider five distinct explanations: the nature of the group itself; characteristics of the group's kin; contagion processes; ethnic security dilemmas; and the end of the cold war. Using logit, we analyze data from the Minorities at Risk data set. Our findings support elements of the conventional wisdom: Ethnic kin influence irredentism, and violence between a group and its host state increases secessionism. Contrary to current debates, groups that are more concentrated are more likely to be secessionist. Further, some factors are less important than usually argued: relative size, a group's ethnic distinctiveness, economic and political differences, regime type, and economic growth.
Journal of Politics

Saideman, S.M, & Ayres, R.W. (R. William). (2000). Determining the causes of irredentism: Logit analyses of minorities at risk data from the 1980s and 1990s. Journal of Politics, 62(4), 1126–1144. doi:10.1111/0022-3816.00049