It all began with German Chancellor Otto von Bismarck. He had two concerns—one, that France might try to reclaim land lost to Germany in the Franco-Prussian War, two that Russia might continue making advances into the Balkans. So, in 1882 he proposed what he considered would be a defensive alliance with the Austro-Hungarian Empire and the Kingdom of Italy, the thought being that the Hapsburgs would contain Russian ambitions, while France would he faced with a two-front war—Germany to the northeast and Italy to the southeast if she attempted an offensive.
Neither the French nor the Russians were happy with Bismarck’s solution. France was left isolated, and Russia felt disrespected, so the answer for their diplomats was to form new alliances. In 1904 France signed the Entente Cordiale with Great Britain. The French had a much larger land army than Britain, but Britain’s fleet was without peer and once hostilities actually broke out, soon proved that control over shipping and the sea-lanes was no small weapon in one’s arsenal. So at this point France could say that if they attacked Germany, Italy would attack them, yes, but Britain and her formidable fleet would move against them both.
Thus far, this system of alliances was, in its own strange way about preventing wars. In essence it was saying, “Look, I’m a little guy, but if you attack me, my bigger stronger friend will attack you.” If Russia thought a victory over Austria-Hungary would be easy, they had to re-think things if suddenly Germany, with the largest and strongest of all European land armies, would move against them. Similarly, if Germany had an urge to attack France, they would be confronted with the mighty Royal Navy.
England further involved herself by signing the Anglo-Russian Convention in 1907. Now, if Russia decided to take on Austria-Hungary, it was true that they would have to face the German army, but Germany and her Hapsburg allies would face retaliation at the hands of the Royal Navy. In theory this would all work as long as the players were rational and took their national interests into account.
But true believers are rarely rational and Young Serbia felt that the Hapsburgs had no place in the Balkans. When Gavrilo Princip fired his pistol, he wasn’t thinking much about the ultimate interests of England, Germany, France or even Russia, “the Mother of the Slavs.”
Now there was an all-but insurmountable problem. Each of the potential combatants, with the exception of Britain and Germany had dealt with politically-motivated assassinations of their heads-of-state, and none of them approved of the custom. Austria-Hungary was the aggrieved party—the heir to their throne and his pregnant wife had been murdered. What were they to do? A volley of pistol-shots had set in motion a machine that there was no stopping.