Preventive war seemed like a good idea at the time. Between 1871 and 1913 the Great Powers considered initiating a preventive war on several occasions, yet in each case civilian and military leaders rejected the strategy. This chapter considers four of these occasions: the War-in-Sight crisis in 1875; the demands of German and Austrian General Staff officers between 1886 and 1888 to attack France and Russia; the First Moroccan Crisis in 1905 and 1906; and the demands of the Austro-Hungarian Chief of the General Staff, Franz Conrad von Hötzendorf, to launch a war against Italy in 1911. In an article devoted to explaining the absence of preventive wars in the 1930s, Norrin Ripsman and Jack Levy noted that “explaining why theoretically unexpected events do not occur is just as important as explaining why theoretically unexpected events do occur.” The cases under consideration in this chapter demonstrate the specific restraints on preventive war in the late nineteenth and early twentieth centuries, while also illustrating how the employment of the concept of preventive war, rather than the actual initiation of a preventive war, functioned in international and domestic politics.

The absence of preventive war in this era of Great Power rivalry is surprising on three counts. First, the theoretical conditions for preventive war, that is, a war motivated by the expectation of a foreseeable deterioration in a state’s relative military power and the fear of a future attack by a currently weaker rival, existed in Europe between the Franco-Prussian War and the First World War. The presence of six Great Powers, whose relative military power shifted on a periodic basis, created opportunities and incentives for preventive war. The shifts in military power were more predictable and more open than in previous eras of European history as states embarked on multi-year armaments programs, and set out their plans and budgets in parliaments and the press.