What were the causes of such a savage war?
Diarmaid Ferriter examines the rapid descent into a broad conflict
Historians have spent decades attempting to establish the reasons for the outbreak of World War I and establishing who was to blame.
There is no consensus on these questions, but most historians place much responsibility on the political and military leaders of Germany and Austria-Hungary, who are regarded as having created the conditions that led to conflict.
Europe on the eve of war was essentially divided into two armed camps. Germany, under Kaiser Wilhelm II, had decided to move away from its traditional co-operation with Russia, opting instead for an alliance with Austria-Hungary.
France and Russia signed an alliance in 1894 and a few years later Germany began to build up its navy, alarming Britain, then the world's most powerful maritime nation, which in response, changed its traditional approach of remaining aloof from international entanglements. Within 10 years Britain had concluded limited agreements with her two major colonial rivals, France and Russia.
By the summer of 1914, Germany was prepared to risk large-scale war and was under pressure from the Austro-Hungarian Empire, which after the assassination in Sarajevo of its Archduke Franz Ferdinand and his wife by a Bosnian Serb, took action against Serbia. It was seeking to conquer and destroy its unstable neighbour, which had sought to expand its borders into Austro-Hungarian territories.
These actions did not make a broader European war inevitable, but in July, Germany offered unconditional support to Austria-Hungary.
The Berlin government famously issued a "blank cheque" to its ally, despite the risk of war with Russia, a supporter of Serbia. Perhaps it believed that France and Britain might refuse to support Russia, thus damaging their alliance, or that Russia, although certain to come to Serbia's aid, would be vulnerable, as it was still rebuilding its military strength after defeat by Japan in 1905.
The governments of imperial Germany and Austria-Hungary conspired to bring about war in the hope that Britain would stay out, but there was one overriding and obvious reason why Britain would respond.
A German victory would be a threat to its security, and for centuries its aim had been to maintain the balance of power in Europe to ensure no state became too powerful; just as Napoleon's France had threatened this, so now did Wilhelm's Germany.
Britain also had a particular sensitivity about Belgium, as Belgian ports in the hands of Germany, one of its war aims, offered a threat to British naval superiority.
If France had been defeated, Britain would have been faced with the continent dominated by a single aggressive state. Neutrality for Britain was hardly an option; how would a victorious Germany have accommodated Britain's naval supremacy and dominance of the international financial system?
France encouraged Russia's aggressiveness towards Austria-Hungary and Germany encouraged Austria-Hungary's intransigence. Britain failed to mediate as it had done in previous Balkan crises out of fear of Germany's European and global ambitions.
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