World War 1 and Archduke Ferdinand

How did the assassination of Archduke Franz Ferdinand in 1914 lead to a war?

Determining the significance of the assassination of Archduke Franz Ferdinand in the larger chain of events that lead to World War I (WWI) requires an understanding of the larger political climate of late 19th century Europe.  There are a three key terms that should be clarified before attempting to understand the complex interaction of events that lead to both Ferdinand’s assassination and one of the bloodiest wars the world had ever seen.  The terms are:
1. Balance of Power
2. "Eastern Question"
3. Brinksmanship