With the UN now past the half-century mark of existence, it is natural to pause and reflect on the organization's role in the management and resolution of a truly global problem: ethnic conflict. No figures, however, are available with respect to the UN's record in responding to communal conflict as manifested at the interstate level. The present study is intended as an initial venture into UN activity in the aggregate, with a specific focus on international ethnic crises. This investigation of the UN and interstate ethnic crises unfolds in four stages. First, the special challenges posed by ethnic conflicts are summarized, leading into a series of propositions about crisis management and outcomes. The second stage presents sources of data and measurement of variables. Third, the propositions about UN activity are tested over the period from 1947--94. In both the full and post-1988 periods, violent crisis management and severe violence become more likely with UN involvement. However, if the UN has not been able to prevent violence in the most difficult situations, it has improved the way that participants view the outcome in a greater proportion of conflicts than in the Cold War era. Fourth, and finally, implications of the results and directions for future research are discussed.