The “othering” of international humanitarian law has a demonstrated past resulting from the exclusion of so-called “Enemies of the Faith” from the laws of chivalry. It is no surprise, then, that the idea of “sharp war” should seem so natural to some commentators given its historical application “by the discretion of the commander and such rules of justice and humanity as recommend themselves in the particular circumstances of the case”. The application of humanitarian principles, in other words, was the measure of the commander's charity rather than the result of legal compulsion.

The viability of sharp war appears to have increased in attractiveness as conventional State-on-State warfare has seemingly decreased in frequency; however, the question of sharp war has never been approached through a legal historical lens. Utilizing the research found in The Laws of Yesterday's Wars, a multi-author series edited by the present author, this paper seeks to fill this gap by scoping over a range of geographically and temporally disconnected case studies and the customary law developed to mitigate warfare. Ultimately, the paper highlights that “soft war” has naturally evolved in all cultures and that arguments for sharp war are a historical anomaly.