Regular War and Resort to Force in the Enlightenment
Chapter 3 turns to the Enlightenment and looks at how Christian Wolff and Emer de Vattel—two of its foremost international thinkers—articulated the doctrine of ius ad bellum in the theory of regular war. The chapter shows that they gave legal weight to both sovereign standing and the justice of the cause, but their views on just cause departed radically from scholastic doctrines of just war. They understood the justice of a cause not in analogy to a legal trial but rather in the context of the international practice of publishing “war manifestoes” that offered plausible reasons for waging war. Such reasons had to be framed in the language of the law of nations and show that sovereigns took seriously state rights, but they belonged to a broad understanding of sovereign judgment in which usually all lawful enemies at war could simultaneously offer plausible reasons for war.