In Operation Cobra, six US divisions, during six dramatic days in Normandy, ended the stalemate on the western front, breaking through German defences after seven weeks of gruelling attrition warfare. After D-Day examines the experiences of US soldiers in the July 25-30, 1944, Normandy campaign: their mistakes, hardships and fears, as well as their leadership, courage and determination. Drawing on original archival sources, Carafano argues that previous accounts of Operation Cobra are flawed. Standard explanations of its success - the forces of air power, innovative tactics, superior logistics, the inestimable value of citizen soldiers, hedgerow busting rhino tanks - are in fact myths. And serious mistakes were made: one of the most famous US generals, Omar Bradley, ordered strategic bombing close to US lines, a decision that led to the killing and maiming of hundreds of US soldiers by friendly fire. Nonetheless, Carafano demonstrates, operation flexibility - the ability of commanders to exercise effective combat leadership and take advantage of troop strengths and material advantages - resulted in Allied victory.