By focusing on the British blockade of Germany, the prevailing narrative over-privileges one aspect of the use of food for belligerent purposes during the First World War. Blockade was not just Britain’s concern. France played a key role in its implementation, especially in respect to land routes and in the Mediterranean. Also, it was not just imposed in the Atlantic approaches. The other seas lapping both Europe and western Asia were vehicles for the application of sea power. In addition, starvation was not just an instrument of maritime warfare: it was also used by armies. Nor was Germany the only target; so too were its allies: Austria-Hungary, the Ottoman Empire and Bulgaria. How the blocking of maritime trade affected their fighting power varied, depending on the management of their domestic food production, their distribution networks and their agricultural workforces. The blockade may have looked like a blunt instrument but its effectiveness depended on its interactions with other conditions, not all of them under governmental or even human control.

This chapter foregrounds practices of colonial warfare, focussing on the transimperial knowledge behind scorched earth and extermination. The first section identifies devastation and hunger war as the most common practice of colonial war, specifically colonial in the way it was racialised, applied ubiquitously and considered self-evident. In line with the book’s argument, it is argued that the contestation and final abandonment of the method by the Dutch in Aceh represent less of a national particularity than it might appear. The second section departs from conventional approaches to colonial genocide and explores how exterminatory practices were part of Western thought on colonial warfare. There were specific war contexts in which extermination became thinkable, even if these were not held to apply to the majority of colonial wars. Thus, somewhat paradoxically, extermination was an inherent and at the same time relatively minor presence in thinking on colonial war. Engaging with theories of German colonial particularity, the chapter applies these findings to the genocide in German South West Africa, showing how the actions and motivations standing behind it fit into broader transimperial patterns.

Chapter 9 delves into juridical military necessity as an exception. It begins by distinguishing juridical military necessity from the state of necessity, a circumstance precluding the wrongfulness of an act under the international law of state responsibility, on account of their distinct normative status and distinct contents. The discussion then proceeds to the four cumulative requirements customary IHL imposes when invoking express military necessity clauses. First, the measure must be taken as primary for some specific military purpose. Second, the measure must be ‘required’ for the purpose’s attainment. This requirement may be sub-divided into three components, namely relevance, minimum injury and proportionality. Third, the purpose must itself conform to IHL. Fourth, the measure must also conform to IHL.