When the Reinsurance Treaty was brought up in 1890, it could have been renewed through clever diplomacy, had Germany sought reconciliation with Russia. However, no such reconciliation was sought and the Treaty that effectively stopped European war through ensuring that France remained isolated was allowed to lapse. However, not only had this agreement been damaged by Bismarck's handling of the San Stefano treaty, but it had been further damaged by Wilhelm II who seemed increasingly in favour of Germany forging closer links with Austria and Italy and pursuing a more expansionist policy. The result was that Russia felt isolated and sought a treaty with France. Russia and France were both bordered by potentially hostile powers and each needed an ally in the event of war. France showed immediate interest in this agreement.
The Entente Cordiale between Britain and France in 1904 and the Anglo-Russian Entente of 1907 effectively ensured that Europe was split by two opposing alliances, the Triple Alliance (Germany, Austria and Italy) and the Triple Entente (Britain, France and Russia.) These alliances were the key that made European war possible however even at this stage war could have been avoided.
The trigger factor was the successful assassination of Archduke Franz Ferdinand by a Serbian terrorist organisation, 'The Black Hand'. This event took place in Sarajevo on the 18th June 1914. It was originally a state visit by the Archduke to the capital. It was the wedding anniversary of the Archduke and his wife Sophie, and they celebrated by driving through the streets of Sarajevo in an open top car. The attempts by the 'Black Hand' were initially unsuccessful a hand grenade thrown at the car missed the intended target injuring onlookers. The officials in charge of the visit decided to change the route, however, a wrong turn was made and as the Archduke's driver tried to reverse, a second assassin fired several shots at point blank range killing the Archduke. The Austrians took the event as a deep affront on their national pride. They felt that in an age where an insult could not be left unavenged somebody must be to blame. The 'Black Hand' were certainly a Serbian terrorist organisation, whether the Serb government had any knowledge of their actions is unsure, but Austria blamed Serbia for the attack. However, if Austria was to commence an attack on Serbia, it was almost inevitable that Russia would get involved. For this reason Austria refused to act without the promise of support from Germany. On July 5th, Austria sent an envoy to Germany requesting permission for a response. Had Wilhelm II refused the Austrian request for support, it is probable that war would have been avoided. So why did the German Kaiser give the Austrians a 'blank cheque' and promise unconditional support to Austria? It is in this action that Germany's responsibility lies, were they planning war, or did they not expect Austria to actually go to war over the event?
Kaiser Wilhelm II was brought up in a liberal family, but a withered arm and having liberalism spoon fed into him from an early age caused him to blame his mother for his withered arm and rebel against her liberal ideas. He became obsessed with the military and surrounded himself with military advisors, This led to policies such as naval expansion, which invoked the ill will of Britain. In December 1912, the Germans held a war council at Potsdam the question is were the Germans planning European war in 1912 or were they simply preparing for the possibility that European war might occur? It seems to me that the conference simply discussed what Germany should do if War did break out. However, the war conference shows that Germany was not reluctant to enter into a war and the Kaiser and his advisors were yearning for expansion of the German Empire saw the potential benefits of a war.
The 'Blank Cheque' given by Germany to Austria did lead to war. This was an extremely difficult and precarious position for the Germans. If they refused to support Austria, they would be accused of leaving Austria to fight alone, and Austria might turn to the Triple Entente. However if Austria were encouraged to pursue a course of action, Germany could have been accused of pushing Europe towards war.
The Austrians wanted revenge, and German backing allowed them to commence a war with Serbia. It was the ultimatum intentionally containing unacceptable terms that Austria offered Serbia that enabled war to commence. On 26th July 1914, Austria declared war on Serbia despite Serbia's acceptance of all except one of the conditions on the ultimatum.
It was predictable that Russia, supported by France, would get involved however Russia initially did not intend to engage Germany. Russia had two schemes for mobilisation, part mobilisation or full mobilisation, the two were not interchangeable, once part mobilisation was ordered, because of the rolling stock required etc. troops could end up stranded miles from the front being rendered utterly useless, the result was that troops were fully mobilise and placed along the entire front.
This again was not an act of war towards Germany, but simply a threat of war, however Russia's full mobilisation allowed Germany to blame the first move on Russia. Despite the entreaties of Tsar Nicholas II, Germany's entire plan hinged upon a Blitzkrieg to wipe out France followed by a concentration of forces on the Eastern Front. For centuries, due to geographical position, Germany had been afraid of a war on two fronts this had caused Germany to draw up a plan known as the Schlieffen plan, which basically involved an attack on France through Belgium, encircling Paris and thereby disabling France which allowed Germany to concentrate on Russia. The plan assumed that it would take months for the Russian war machine to get moving giving Germany enough time to achieve victory against France. The result of this plan was that as soon as Germany declared was on Russia, the trains went west, through Belgium to attack France.
So, to what extent was Germany responsible for the First World War if you consider that the Alliance system rendered war inevitable, then it can be said that Germany was entirely to blame. It was Germany's Triple Alliance with Austria and Italy that began the system of Alliances under Bismarck. Germany can also be held responsible for the lapse of the Reinsurance treaty with the result of a Franco-Russian alliance followed closely by a Triple Entente between Russia, Britain and France. However these alliances cannot be entirely blamed for the war.
The war came about because of the mismanagement of a crisis. The assassination of Archduke Franz Ferdinand should not have led to war. However, it was the spark that lit the fuse in an atmosphere of hostility. The communications breakdown between the two 'camps', led in many ways to the commencement of war. Again Germany played a role in the mismanagement of the Balkans crisis, although in this case I think that a large part of the blame can be laid on Austria. If Austria had not decided that the most appropriate form of revenge was war, then perhaps a full scale European war could have been averted. It was the unacceptable ultimatum, and consequent declaration of war on Serbia that led to the involvement of Russia and a fight between the alliances.
However it was the promise of unconditional support from Germany that allowed Austria to act. It is difficult to understand why Germany did this but it is most likely that either Germany wanted war or that she trusted Austria not to go to war. Either way it is because of Germany's 'Blank Cheque' that Austria was able to go to war with the full support of its powerful ally.
Russia's full mobilisation caused Germany to feel threatened, and as their plan relied upon surprise attack on France before turning east to concentrate on Russia. However Tsar Nicholas II was forced to mobilise fully right across the front because of the practicalities of mobilising the huge Russian army if communication between Russia and Germany had been better the crisis could have been controlled by an explanation of actions on Russia’s part as both Nicholas II and Wilhelm II seemed intent on averting war.
In conclusion, Germany can certainly be blamed for causing the hostile atmosphere that had developed by 1914 due to the alliance system, and also for giving Austria unconditional support in the Balkans crisis. However you can not only blame Germany for the outbreak of war. Austria's loss of status and subsequent wish to restore itself as a great power through war and revenge on Serbia is also to blame. Russia mobilising its troops was also important in the outbreak of war. Germany can be blamed partially for the outbreak of war, but other factors and other countries played an important role in the out break of war in 1914.