Book excerpt: The battle of Tannenberg (August 27-30, 1914) opened World War I with a decisive German victory over Russia-indeed the Kaiser's only clear-cut victory in a non-attritional battle during four years of war. In this first paperback edition of the classic work, historian Dennis Showalter analyzes this battle's causes, effects, and implications for subsequent German military policy. The author carefully guides the reader through what actually happened on the battlefield, from its grand strategy down to the level of improvised squad actions. Examining the battle in the context of contemporary diplom.