A momentous battle is taking place over dominance of the enormous market for commercial jetliners. Europe's Airbus and America's Boeing each seek to cripple their rival with better products, more attuned to the needs of the airlines and the flying public. The lead has passed back and forth between the two, with Airbus surpassing Boeing in sales and deliveries in recent years. But Boeing, playing a canny strategy, may have outwitted its rival. At least for the present.

The outward signs are somewhat prosaic. A seemingly routine announcement by Boeing that it will offer a stretch version