Roots and Branches

Jus post bellum is commonly considered a new and novel concept. But it does have a deeper historical pedigree; and this past is of relevance for its future, both as concept and as practice. This chapter argues that the most plausible contender for ‘inventor of jus post bellum’ in its unique, substantive, recognizable, and forward-looking form, is the German philosopher Immanuel Kant (1724–1804). The main aim of this chapter is not to defend such a purely historical claim. It is, rather, to show in detail all that Kant had to offer regarding the jus post bellum: how he develops it in both a short-term (procedural) sense and a long-term (substantive) sense, ranging from immediate ceasefires and public peace treaties all the way to the worldwide spread of a cosmopolitan federation devoted to peace and the realization of everyone’s human rights.