In a continuing effort to determine the ethnic correlates of third-party interventions in civil wars, this paper probes questions of whether particular structural relations between ethnic groups in potential interveners affect their inclination to intervene. I have argued in an earlier paper that transnational ethnic affinities cause interventions through a range of cross-border power configurations. Here, I investigate the proposition that ethnically dominant states are more prone to intervene than ethnically pluralist states, given that their dominant ethnic group has ethnic kin in the target country. The hypothesis is tested on data on third-party interventions in civil wars in Eurasia and North Africa 1944-1994. I alternately apply nine different measures of ethnic domination or polarisation typically used in the quantitative literature on the onset and incidence of civil wars. The statistical analyses suggest that the measures with the strongest theoretical foundation best express the effect of ethnic domination on intervention-proneness. Under the specified conditions, ethnically dominant states are indeed more likely to intervene than their ethnically pluralist counterparts.