Excerpts from Books and Wikipedia
"The nightmare of World War I began on August 4, when the German armies streamed over the Belgian border. After Britain had demanded in vain that the Germans withdraw, she declared war at 11 PM. By 1914 the division of Europe into two rival armed camps was well advanced. Fearing encirclement and Russia's growing military strength, the Central Powers of Germany and Austria-Hungary we're convinced that they could win a preemptive war against the allies Russia and France without Britain joining in. . . . When Germany used the assassination of the Austrian heir apparent Archduke Franz Ferdinand by a Serb nationalist as a casus belli to provoke Serbia's ally Russia into the war, her own war plans had long been laid. The plan involved violating Belgian neutrality to invade France and seize the Channel ports. . . . Germany gambled that Britain would not declare war and that, even if she did, Germany would be able to crush France before British power was brought to bear." [Furtado: 1001 Days]