Before the Iran war, Qatar was one of the biggest natural gas exporters in the world. After only eight months, the Gulf state is now buying supplies from its principal competitor — the United States. QatarEnergy struck a deal Thursday with U.S. exporter Cheniere Energy to buy 4 million metric tons of liquefied natural gas (LNG) annually through 2054. The purchase price is indexed to the U.S. Henry Hub price plus a fixed fee. Deliveries are expected to begin in the 2030s. “We look forward to reliably supplying QatarEnergy from both Sabine Pass and Corpus Christi into the second half...