The abolition of slavery and the end of international war

Slavery and war have both historically been considered inevitable consequences of human nature. Yet slavery has been abolished, and moral progress may have contributed to slavery's disappearance. Both realists and Marxists are skeptical about the impact of ethical constraints on political decisions, while idealists as well as at least some regime analysts emphasize the role of those constraints. However, elements of all of these approaches support the proposition that moral progress may bring an end to international war.Some historical trends do not support the idea that international war is on the verge of disappearance, but there has not been a war between major powers since 1945. In addition, norms against colonialism are strong. No war has occurred between democratic states, nor does a war appear likely among the rather sizable number of industrialized democratic states in the international system today. Explanations of these pockets of peace based on caution induced by nuclear weapons or on economic interdependence, for example, are certainly not beyond question. Therefore, it may be that norms inhibiting the initiation of international war have already made obsolete not only wars between the richest and most powerful states in the world but also some forms of depradation by the strong against the relatively weak states.