Research related to conflict resolution and peace that combined psychological factors with political or economic ones was relatively uncommon before the 1990s. Research in international relations might dwell on power politics, for example, and economic paradigms might describe strategies for achieving maximum profit as a function of wholly rational choices. Such work has yielded valuable findings – for instance, two bargaining parties are likely to achieve maximum joint profit if even one of them successively explores resolutions at the frontiers of diminishing profit. It has become increasingly common, however, for such research to be genuinely interdisciplinary and to take account of social, cognitive, motivational and other psychological factors (see, for example, Etheridge, 1992).

The present chapter covers research related to ethnopolitical violence, social psychology and personality, core concerns of international relations (including aspects related to interpersonal relations and motivation), deterrence and arms control, democracy and alliances, and the United Nations and other international bodies.

Ethnopolitical conflict

Among the key factors that determine whether ethnopolitical (often intrastate) violence is likely to escalate are ingroup identification coupled with what Deutsch (1986) has called a malignant (spiral) process of hostile interaction.