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.