Chris Clark's study of the outbreak of the First World War ,The Sleepwalkers: How Europe Went to War in 1914, appeared in English in 2012:[7] the German version followed in 2013. The book challenges the imputation, hitherto widely accepted by mainstream scholars since 1919, of a peculiar "war guilt" attaching to the German Empire, instead mapping carefully the complex mechanism of events and misjudgements that led to war.[8][9] There was, in 1914, nothing inevitable about it. Risks inherent in the strategies pursued by the various governments involved had been taken before without catastrophic consequences: this now enabled leaders to follow similar approaches while not adequately evaluating or recognising those risks. Among international experts many saw this presentation by Clark of his research and insights as groundbreaking.[10] In Germany itself, where the book received much critical attention, reactions were not all positive. Volker Ullrich contended that Clark's analysis largely disregards the pressure for war coming from Germany's powerful military establishment.[11] According to Hans-Ulrich Wehler (1931-2014) Clark had diligently researched the sources covering the war's causes from the German side only to "eliminate [many of them] with bewildering one-sidedness" ("verblüffend einseitig eliminiert"). Warming to his theme, Wehler attributed the sales success of the book in Germany to a "deep seated need [on the part of German readers], no longer so constrained by the taboos characteristic of the later twentieth century, to free themselves from the burdensome allegations of national war guilt".