Diplomatic History/World War I
World War I marks a dramatic watershed in the history of Europe and the world. Although it started as a minor skirmish in the Balkans it soon escalated to the point that most of the world's major powers were involved in a war more destructive than any the world had ever known. The social and diplomatic consequences were enormous and felt across the world. Empires fell, political systems were severely tested, and many of the old mindsets were destroyed.
The reasons for the outbreak of war in August 1914 are diverse and varied. However, the immediate reasons for the outbreak are relatively simple. Gavrillo Princip, the member of a group working for Bosnian independence from Austria-Hungary shot the heir to the throne of that state, Archduke Franz Ferdinand and his wife.
At the same time, many members of the Austro-Hungarian government were looking for an excuse to attack Serbia, and because of connections between the cause of Princip's slavic nationalist group and the supposed aims of the Serbian government, they felt this was the perfect excuse. They presented a list of demands to the Serbian government, which it was inclined to accept except for one demand which was expressly designed to be rejected. As a result Austria-Hungary declared war on Serbia.
The complicating factor in this situation was the interest of Russia in the region. Due to feelings of community, known as pan-slavism, which unified the people of Russia and Serbia. Russia felt that it could not allow an attack on Serbia to go unchecked. Although they made this clear, Austria-Hungary had assurances from Germany that they would support them in the case of a Russian attack, so the leadership felt confident that they could still defeat Serbia in time to handle a Russian attack.
However, because of Russia's defence treaty with France, Germany was more concerned by France than Russia. As a result they initiated a plan to defeat France before turning to Russia that involved an attack against Belgium. In the 19th century Britain had made assurances to Belgium that it would protect Belgium's neutrality, so after the German invasion Britain also declared war on Germany.
Thus, through a series of alliances all of Europe's major powers were brought into conflict, ostensibly over the boundaries of Serbia.