It's no consolation to the refugees huddled in airports around the world, but the truth is that the global air-travel system is a technological marvel, capable of getting you to the other side of the planet in less than a day. Just not these days, thanks to a series of late-December wintry blasts that shut down swaths of Western Europe, immobilized Moscow's airports and buried the northeastern U.S. Air travelers had it the worst, especially those who wanted to get to or from New York City, where all three of the area's airports--which handle about one-third of U.S. flights--were shut down for a time. Thousands of flights were canceled, and the ripples quickly spread worldwide, leaving passengers stranded in Atlanta's Hartsfield-Jackson, London's Heathrow and Hong Kong's Chek Lap Kok. It was inevitable. Airlines have cut their schedules to the bone, leaving no wiggle room to cope with weather madness, let alone true catastrophe. In time, of course, the snow will melt and the runways will clear, but the storms served as a cold reminder: air travel may be a miracle, but it's a fragile one.