Contrary to the flag-waving mythology of World War II, America did not hurl herself wholeheartedly into the Allied war effort like some ferocious she-wolf defending her young. Emerging from the Great War a gun-shy, cautious, and fiercely isolationist country, the U.S. was deeply reluctant to enter this second war in Europe, even in the face of outrageous Nazi aggressions. It was only the blatant attack on Pearl Harbor that galvanized Congress into declaring war on Japan (and then, only after assurances that public opinion had changed). Once engaged, the American "war machine" was plagued by slow-grinding gears. At every turn, costly half-measures, political infighting, military bungling, slow mobilization, and other tragic mistakes nearly derailed the war effort. Nevertheless, the U.S. won great, decisive, victories on both fronts. This far-ranging domestic, military, and diplomatic history explains how. B&W photos.