 According to Hans-Ulrich Wehler, 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"

Vernon Bogdanor has criticized Clark for downplaying the German and Austrian refusal of offers of mediation.Over the course of the July Crisis Sir Edward Grey, British Foreign Secretary, offered a four-power conference of the Great Powers to help mediate the conflict.