World War Terrible Twos? Help is at hand. In a war, you need slogans. For public safety and morale, and all that jazz. Now, of course, in this war, no one has time to be coming up with slogans ...

One of the subtlest and most surprising legacies of the First World War—which the United States entered 105 years ago, when the country declared war on Germany on April 6, 1917—is its effect ...