Book excerpt: An inventive study of relations between the National Guard and the Regular Army during World War II, Guard Wars follows the Pennsylvania National Guard's 28th Infantry Division from its peacetime status through training and into combat in Western Europe. The broader story, spanning the years 1939--1945, sheds light on the National Guard, the U.S. Army, and American identities and priorities during the war years. Michael E. Weaver carefully tracks the division's difficult transformation into a combat-ready unit and highlights General Omar Bradley's extraordinary capacity for leadership -- which turned the Pennsylvanians from the least capable to one of the more capable units, a claim dearly tested in the Battle of the HÃ1⁄4rtgen Forest. This absorbing and informative analysis chronicles the nation's response to the extreme demands of a world war, and the flexibility its leaders and soldiers displayed in the chaos of combat.