That was the catalyst that lit the inferno that started World War I.Barbara Tuchman's famed history book"The Guns of August" covers the whole deal spiel -- for when Austria-Hungary lost its leader they took revenge on Serbia. Ambitions in Russia and France were ignited, launching a disaster for them all.
Austria-Hungary alliance was frontloaded with inept diplomacy, leaked intentions and poor military readiness gave Russia a month to prepare for a much larger war, alarming peasants from Constantinople to Berlin.
France's president Raymond Poincare sailed into St. Petersburg, where his ambassador to Russia heard from Grand Duchess Anastasia, wife of the future army commander Grand Duke Nicholas Nicholaevich, "There's going to be war. There's nothing left of Austra. You're going to get back Alsace and Lorraine. Our armies will meet in Berlin. Germany will be destroyed," she told him gleefully.
Germany's great mistake was invading Belgium to flank the French, writes Sean McMeekin in "July 1914: Countdown to War." What started as a Balkan conflict morphed into a war -- with the Russians coming in on the side of Germany and Austria-Hungary and the British sided with France and Russia. Germany was outnumbered on two fronts and the Brits controlled the seas.