The events of July and early August 1914 are a classic case of “one thing led to another”- otherwise known as the treaty alliance system.

The explosive that was World War One had been long in the stockpiling; the spark was the assassination of Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, in Sarajevo on June 28, 1914. Ferdinand’s death at the hand of the Black Hand, a Serbian secret society, set in train a mindlessly mechanical series of events that culminated in the world’s first global war. Austria-Hungary’s reaction to the death of their heir was three weeks in coming. Arguing that the Serbian government was implicated in the machinations of the Black Hand, the Austria-Hungarians opted to take the opportunity to stamp its authority upon the Serbians, crushing the nationalist movements there and cementing Austria-Hungary’s influence in the Balkans.

It did so by issuing an ultimatum to Serbia, which in extent of its demand that the assassins be brought to justice effectively nullified Serbia’s sovereignty. Austria-Hungary’s expectations were that Serbia would reject the remarkably severe terms of the ultimatum, thereby giving her pretext for launching a limited war against Serbia.
Austria-Hungary unsatisfied with Serbia’s response to her ultimatum declared war on Serbia on July 28, 1914. Russia bounded by treaty with Serbia, announced mobilization of its vast army in defense, a slow process that would take around six weeks to complete.

Germany, allied to Austria-Hungary by treaty, viewed the Russian mobilization as an act of war against Austria-Hungary, and after scant warning declared war on Russia on 1 August. (more…)