How many times have you been jerked around at an airport and made to wait in several long lines after a flight delay or cancellation forced a change to the rest of your itinerary? Chances are, that happened abroad. For all their faults, U.S. airlines handle irregular operations better than their foreign peers.

I’ve always wondered why airport agents in the United States — whether at check-in counters, gates or even business lounges — can do almost anything a passenger needs, including rebooking, rerouting and reissuing tickets, while agents in other countries are much more specialized, and thus less helpful…