It isn’t easy to put U.S. defenses back on track after they’ve endured a season of neglect. Gen. William Snow found that out firsthand. Snow’s job, when he arrived in Washington in the World War I era, was to direct the buildup of artillery for the Allied Expeditionary Force. He thought his office should have stationery reflecting the importance of the task. His request was rejected. Rather than fund this extravagance, it was suggested the general purchase a rubber stamp to mark his correspondence. Snow had joined a War Department completely unprepared to fight a war. The Army hadn’t been...