How a Shooting in a Town Few Had Heard Of Helped Start a War Whose Deaths, With Its Aftermath, Reached 40 Million

In the summer of 1914, Europe felt peaceful. Statesmen were focused on problems at home, not on war abroad, and few people in Britain or France had ever heard of Sarajevo. Then the man next in line to rule Austria-Hungary was shot there, and within days Europe was moving fast toward a war whose deaths, with its aftermath, reached 40 million people.

That is the puzzle Odd Arne Westad, who has written a new book on the lead-up to the First World War, tries to explain. Below the calm surface, he says, tensions had been building for some time among all the great powers that would end up fighting. People in Britain, France, Germany, and especially Austria were growing worried about their relative positions.

The assassination was a terrorist act, and "it came at the worst possible time," Westad says. Many leaders were looking inward at their own domestic troubles even as they worried about where their countries stood.

After the killing, Austria, the weaker ally, took action. Germany, a very powerful country behind it, was not willing or able to hold it back. Austria's move unraveled the whole European system.

Westad points to the first sign of losing control in Germany itself. Germany's emperor, Kaiser Wilhelm II, cut short his annual holiday in Norway and returned to Potsdam furious at being recalled for another Balkan crisis.

About 36 hours after that return, the Kaiser and his advisers saw that this crisis was different and could not be stopped, because, in Westad's words, "the wheels are already in motion."