I used to fly frequently between England and Japan in the 1970s, often passing at 33,000 feet over the Arctic icecap and landing to refuel in Anchorage, Alaska. There, the airport was sometimes thronged with U.S. troops on their way to or from Vietnam.

My brothers and I found a sticker in a copy of Mad magazine, of which we were avid in-flight readers, bearing a photograph of President Richard Nixon and the question, “Would You Buy a Used War from this Man?” We adolescent know-it-alls stuck the sticker on the glass of a portrait of Nixon displayed in the departure lounge, where it produced the knowing grins and disapproving frowns we’d hoped for from military men passing by.