Following the assassination of the heir to the throne, Austria-Hungary considered taking military action against Serbia. Thereupon Kaiser Wilhelm II declared that Germany would support the Danube monarchy as required by alliance obligation – this was the so-called blank cheque.
What became later known as the July Crisis of 1914 began with an exchange of letters. On 5 July 1914 Austro-Hungarian Emperor Franz-Joseph wrote to Kaiser Wilhelm II indicating that he was considering taking military action against Serbia. His motive was the assassination of the heir to the Austro-Hungarian throne, Archduke Franz-Ferdinand, in Sarajevo a few days previously. The Emperor and his top officials were convinced the neighbouring country of Serbia was behind the attack and had given the assassins instructions and weapons. However, there was no proof at this stage of any actual involvement or complicity in the attack on the part of the Serbian Government.
“As required by alliance obligations”
Despite this, Berlin fully backed the Austro-Hungarian line and its reply was soon forthcoming. On behalf of Kaiser Wilhelm II, Reich Chancellor Theobald von Bethmann Hollweg on 6 July 1914 sent a telegram to the German Embassy in Vienna. In this telegram the German Kaiser pledged to ”stand by Austria-Hungary, as is required by the obligations of his alliance and of his ancient friendship.“ In the draft of the telegram, now in the keeping of the Federal Foreign Office’s Political Archive, the addition ”under all circumstances“ has been deleted.
In 1879 the Danube monarchy and Germany had concluded the so-called ”dual alliance“; later on Austria-Hungary increasingly became Germany’s most important and virtually sole ally. Nevertheless, the German Empire’s top officials were well aware of the risks associated with the so-called blank cheque. The geopolitical situation was tense. South-Eastern Europe was where the Austria-Hungarian and Russian spheres of influence intersected. In the preceding years Serbia had moved ever closer to the Czarist empire. It is possible that the authorities in Vienna and Berlin hoped despite this to keep the conflict local – a vain hope, as it turned out over the following weeks and months. In retrospect the ”blank cheque“ is seen as a milestone leading to the outbreak of World War I.