A masterful book by a wonderful historian. No one knows more about the Battle of Tannenberg than Dennis Showalter. He expertly uses archival evidence, official histories, and first-hand accounts to give us the most subtle and persuasive account of the full meaning of this key battle of the Great War. Along the way, he teaches us a lot about how armies fight in the first few weeks of a war. Even the much-vaunted German Army made mistakes, as Showalter clearly shows. Yet, their system was able to recover from these mistakes far more quickly than the blundering Russians. Even so, Tannenberg was decisive only in prolonging the war--not in ending it. Showalter points out the many ironies of this battle that will resonate with readers today. A great book; its only fault is its slow beginning.