"In September 1939, when Nazi Germany invaded Poland and initiated World War II, a strong strain of isolationism existed in Congress and across the country. The U.S. Army stood at fewer than 200,000 men--unprepared to defend the country, much less carry the fight to Europe and the Far East. And yet, less than a year after Pearl Harbor, the American army led the Allied invasion of North Africa, beginning the campaign that would defeat Germany, and...