But if all this alliance talk seems somehow stilted, it is. The missing element is us passengers.

Going all the way back to the BA-US Air pairing, carriers have promised that alliances would offer fliers seamless global connections, simplified prices, consistent service, and a raft of soft benefits such as frequent-flier program reciprocity and interchangeable club-access privileges. The reality has always fallen far short of the promises.

United Airlines, for example, denies members of its Mileage Plus frequent-flier program access to many award seats available on its Star Alliance partners. Although the rules specifically allow it and the airline promotes the awards, the carrier has bluntly said that it would be too costly for United to buy all of the seats on partner airlines that Mileage Plus members try to claim. The discussion boards at FlyerTalk are rife with posts from outraged international flyers who were denied entry to an airport lounge operated by one alliance partner or another. On a more practical note and despite the growth of so-called co-located airport terminals, no alliance can ensure that their flights operate anywhere near the connecting service operated by an alliance partner.

Any flier who's ever lost a bag or had a flight disruption on a code-shared itinerary can tell you how little impact an alliance has on the actual travel experience. More often than not, carriers shift the blame and responsibility to each other rather than treat the traveler as a customer of a seamless alliance. Usually, the traveler is forced to bounce back and forth between individual airline power centers in order to locate the lost bag or rebook the busted itinerary.

Or then there's this tidbit from Continental's defection to Star. Continental operates a two-class in-flight configuration (coach and business) on its international routes. That's at odds with many of its new Star Alliance partners such as Lufthansa, Singapore, South African Airways, All Nippon, and Air New Zealand. They offer at least three classes of in-flight service. Where's the consistency and opaque experience if each alliance partner offers a different type of in-flight service?

Of course, carping about the internal logic or cross-carrier passenger service you'll experience within any particular alliance is a fool's game, one best left to travelers who believe the soaring rhetoric of airline chief executives and the mostly hollow promise of the alliances' promotional campaigns.

"Alliances are not about you," Jack Foley, executive vice president of Aer Lingus, told me in 1999 when the Irish carrier joined Oneworld. "Alliances are about what is good for airlines, not passengers."

The Fine Print… Aer Lingus left Oneworld in 2007, and the growth of that alliance has stalled because regulators on both sides of the Atlantic worry about granting wide-ranging antitrust immunity to American Airlines and British Airways. The two carriers control a large portion of the U.S.-U.K. market and a huge percentage of the takeoff and landing slots at London's Heathrow Airport. Previous antitrust requests (in 1996 and 2001) floundered when BA balked at surrendering slots at Heathrow. The Financial Times implied this week that regulators will once again demand BA give up Heathrow slots as the price of an antitrust exemption.