When war raged through Europe in the summer of 1914, the American public wanted nothing to do with it. Not our war, they said. President Woodrow Wilson agreed. He pledged neutrality for the United States. But over the next few years, three incidents turned public option away from isolationism to one of wanting to take action against Germany and its allies. First was when a German submarine torpedoed the British-owned passenger liner Lusitania without warning, killing 1,2,00 passengers,...