Austria-Hungary and its involvement leading up to the great war (1906-1914)
Blank Check (1914)
After the assassination of Archduke Franz Ferdinand, Wilhelm II gave the country a "blank check" (or blank cheque). The purpose of the blank check was to ensure Austria-Hungary that Germany would give unconditional and full support to any actions Austria-Hungary was going to take towards Serbia. This allowed Austria-Hungary to have complete assurance from the country of Germany.
The blank check gave Austria-Hungary more confidence to battle against Serbia. They had complete support from Germany which motivated Austria-Hungary even more to push for war against Serbia.
"Finally, as far as concerns Serbia, His Majesty, of course, cannot interfere in the dispute now going on between Austria-Hungary and that country, as it is a matter not within his competence. The Emperor Francis Joseph may, however, rest assured that His Majesty will faithfully stand by Austria-Hungary, as is required by the obligations of his alliance and of his ancient friendship. "