A century ago this month, Europeans stood on the brink of a war so devastating that it forced historians to create a new category: “World War.” None of the leaders at the time could imagine the wasteland they would inhabit four years later. By 1918, each had lost what he cherished most: the kaiser dismissed, the Austro-Hungarian Empire dissolved, the tsar overthrown by the Bolsheviks, France bled for a generation, and England shorn of the flower of its youth and treasure. A millennium in which European leaders had been masters of the globe came to a crashing halt.
What caused this catastrophe? President John F. Kennedy enjoyed needling colleagues with that question. He would then remind them of his favorite answer, quoting German Chancellor Theobald von Bethmann Hollweg: “Ah, if we only knew.” When, in the Cuban Missile Crisis of 1962, Kennedy found himself “eyeball to eyeball” with Soviet leader Nikita Khrushchev, making decisions that he knew could mean quick death to 100 million people, he reflected on the lessons of 1914. At several decision points, he adjusted what he was inclined to do in an effort to avoid repeating those leaders’ mistakes.
As they were choosing to fulfill commitments, or not, to mobilize forces sooner or later, the participants in the First World War were simultaneously seeking to frame public perceptions of the crisis. Each sought to blame its adversary. In the aftermath of the catastrophe, the victors took considerable liberty with the facts to justify punishing the vanquished. The Treaty of Versailles imposed such draconian penalties that it created conditions in which, just two decades later, the Second World War erupted. This larger drama has understandably shaped historians’ accounts of the causes of the war. But as the best of the new books on this conflict, Christopher Clark’s The Sleepwalkers, concludes forthrightly, the available evidence can be marshaled to support an array of competing claims. “The outbreak of war in 1914 is not an Agatha Christie drama at the end of which we will discover the culprit standing over a corpse in the conservatory with a smoking pistol,” Clark writes. “There is no smoking gun in this story; or, rather, there is one in the hands of every major character.”