War broke out in the summer of 1914 because several of the nations of
Europe had differences that could not be settled by peaceful means. The
diplomats continued to do their work up to the moment that the first soldiers
passed into the territory of the enemy. Their efforts were unavailing.
There were deep and painful conflicts among the countries of Europe
that led to the unprecedented calamity of a war that lasted four and a half
years, that killed more Europeans than any event since the Black Death of
the fourteenth century, and that altered the shape of European life and the
geopolitical map. Princip's rash act, two shots fired without aiming by a lad
of nineteen who had just learned to use a revolver, set the crisis in motion.
World History
