The shot that changed the world rang out on a sunny summer's morning in Southeastern Europe. No one knew then that the assassin's bullet would spell the death not just of an Austrian aristocrat but the entire global order, with four empires and millions of lives lost in a conflict on a scale never before seen.
Exactly 100 years ago Saturday, Franz Ferdinand, heir to the throne of the Austro-Hungarian empire, and his wife, Sophie, were shot at close range by a young Serbian nationalist on the streets of Sarajevo.
The assassination set off a chain reaction that, barely a month later, culminated in a continent at war.
What many thought would be a brief, even heroic,...