The First World War was an unprecedented catastrophe that killed millions and set the continent of Europe on the path to further calamity two decades later. But it didn’t come out of nowhere. With the centennial of the outbreak of hostilities coming up in 2014, Erik Sass will be looking back at the lead-up to the war, when seemingly minor moments of friction accumulated until the situation was ready to explode. He'll be covering those events 100 years after they occurred. This is the 78th installment in the series.