Austria-Hungary's political and military leaders declared war on Serbia on 28 July 1914. The first act of hostilities came the next day with the bombardment of Belgrade. Using the assassination of Archduke Franz Ferdinand as the pretext, the leaders' aim was to end the Serbian agitation that, in their view, posed a serious threat to the Dual Monarchy. In the thirty days that intervened between those dates, the leaders in Vienna took a series of steps whose purpose was to bring about that war. The most important of these, one taken early in July, was to assure the support of Germany, their powerful ally. Some efforts were made to gain the support or sympathy of other nations or, alternatively, to discourage their active hostility. One central concern was to prevent Russian participation, to limit the conflict, to keep it a “localized” Austro-Serbian war. Decisions were made with regard to the call-up and use of the armed forces. Each of these decisions required planning with respect to timing and sequence. The question of timing led to some division of opinion between the allies, Germany's leaders pressing for an early response. But, as seen below, several considerations led the Austro-Hungarian leaders to delay.

Two conclusions deserve special emphasis, ones that might easily be lost in the complexities of this and the following chapters: In July 1914, Austria-Hungary's leaders were the first to opt for war, and they did so with plan and foresight.