ABSTRACT
Tracing the historic roots of the contemporary legal regime on the use of force is a complex affair. At the end, just like when describing the history of international law as such, it all comes down to the viewpoint and the definitions of war and law. Modern thinking on the ius ad bellum has started with just war theory, which was slowly but steadily superseded by positivism and the conceptualization of war as a sovereign prerogative. The rise of legal positivism during the nineteenth century led to the abandonment of moral considerations and just war theory. The horrors of World War I shuttered the European/Western claim to moral and civilizational superiority. The emphasis on the sovereign prerogative gave way to co-operation, universalism and a first attempt to establish a legal mechanism on the resort to force.
