France had not aided Russia when she reacted against the Austrian annexation of Bosnia Herzegovina. According to A.J.P. Taylor, the alliances were already in a weak point by 1911. Therefore we can clearly appreciate the alliance system, although important, is not the main factor responsible for the outbreak of the war, since it was used as an excuse by the European powers.
Pride and Nationalism.
Nationalism was, undoubtedly, one of the major causes of the outbreak of the war. There were three different kinds of nationalism that helped this conflict to develop.
First, there was the nationalism of the different nationalities in Austria-Hungary, which lead to threats to the stability of the Austrian Empire. This situation made the government especially alert to confront and extinguish any direct or indirect threat to its power. But this also lead the Austrians to look forward for a short, easy war that would unite them, by facing a common enemy and that would give strength to the Empire after having won it.
There was also the issue of nationalism of the great powers. For example, in Germany there were organizations like the Pan-German League and Navy League, which pressed for power and were eager to show their strength in a war. Russian people forgot their domestic problems and supported the army as soon as the war was declared. The press also played an important role in this, since its message was mainly of enthusiasm for national prestige in all countries. .
The third nationalist issue was the affronted great power nationalism. Russia had been humiliated by Austria in the annexation of Bosnia, Germany by France and Britain in the crisis at Agadir. These situations left tension in Europe and a conviction in these countries that if such a humiliation was to happen again, a war was to inevitably break out.
The "blank cheque"- Germany's support to Austria.
After the assassination of the archduke Franz Ferdinand in Sarajevo, the Austrian government saw their great opportunity to take over the kingdom of Serbia, which was becoming a potential dangerous neighbor for the Austrians.