On July 23, 1914, Austria-Hungary sent an ultimatum to Serbia over the assassination of Archduke Franz Ferdinand in Sarajevo by Serbian nationalists. Basically, Austria-Hungary demanded that Serbia surrender its sovereignty in regards to how it dealt with Austria-Hungary, that Austrian officers be part of the investigation into Serbian involvement in the assassination, and that government officials in Serbia be arrested. The Serbs were given 48 hours to unconditionally comply. Serbia, in an attempt to avert war, ascquiesced to these demands, except for the point that Austrian officers be allowed to investigate Serbian citizens. Austria-Hungary began preparing for war with Serbia.
Austria-Hungary declared war on Serbia on July 28, beginning a conflict that would kill millions and throw most of the world into chaos for the better part of a century. Russia, the self-styled protector of the slavic people, partially mobilized its military against Austria-Hungary on July 28, and called a full mobilization on July 30. Germany responded with mobilization of its own.
All this came to a head on August 1, as Germany declared war on Russia. Germany occupied Luxembourg on August 2, the same day it demanded that neutral Belgium allow German troops to transit the country on their way to France. Finally, Germany declared war on France on August 3, giving Great Britain a reason to go to war with Germany.
A final ultimatum was sent by the British to Germany on August 4, demanding that Germany leave Belgium immediately, and that a response from the German government must be sent within hours. As the time limit for this ultimatum ended, Great Britain entered the war, bringing in the last great power that would fight in the war until 1917.
Between all of these events was a flurry of diplomacy, both to head off the war and to encourage it. Calls for multilateral conferences were made and ignored, as were offers for one-on-one negotiations. From reading about the work of the diplomats, half of them seem almost naive in their belief that a general war could be avoided, if not war altogether, while the other half seem almost evil in their machinations to goad the nations of Europe into the fire.
As I read the history of this period, the thing that strikes me is how apathetic a lot of the leadership seemed to be when it came to preventing the war and how much a slave to the process of going to war they were.
Austria could have accepted the answer from Serbia. Russia could have stayed out of the war by telling the Serbs to take their lumps for killing the Austro-Hungarian successor. Germany could definitely have kept to its own business by not mobilizing against Russia and by not invading Luxembourg and Belgium. Great Britain could have been more forceful in its efforts to deter Germany and Austria. All of these countries’ leaders seem to have ridden the wave of history, rather than directing it.
Once the dominoes of mobilization and ultimatums began to fall, all of these leaders refused to pull out the next one in order to stop the avalanche. Wilhelm, the German Kaiser, allowed himself to be cowed into continuing with the Schlieffen Plan by Moltke, his chief of staff, when he suggested that the invasion of Belgium be called off. Nicholas changed his mind about mobilization after being browbeaten by his generals. If either of these men had stood up to their subordinates, the war might have been avoided or at least contained.