Napoleon delayed his attack at Waterloo to allow the mud to dry. Had he attacked earlier, he might have defeated Wellington before Blücher arrived. In November 1942, Russian mud stopped the Germans, who could not advance again until the temperature dropped low enough to freeze the mud. During the Vietnam War, 'Project Popeye' was an American attempt to lengthen the monsoon and cause delays on the Ho Chi Minh Trail. Soldiers have always known just how significant mud can be in war. But historians have not fully recognized its importance, and few have discussed the phenomenon in more than a passing manner. Only three books—Military Geography (by John Collins), Battling the Elements (by Harold Winters et al.), and Battlegrounds) (edited by Michael Stephenson)— have addressed it at any length and then only as part of the entire environment's effect on the battlefield. None of these books analyzed mud's influence on the individual combatant. Mud: A Military History first defines the