Vladimir Putin has waged an energy war on Europe. The general running his campaign is ultra-loyalist and Gazprom PJSC boss Alexei Miller. ... Handicapping Gazprom is Mr. Miller’s decision over the past decade not to enter the market for liquefied-natural gas—a choice that left Gazprom, unlike Russian rival Novatek JSC, near totally reliant on pipelines to export fuel. Gazprom has limited options in the short term to redirect its gas to China and other buyers given its traditionally westward-facing infrastructure. One pipeline to China opened in 2019, but it can’t handle much gas. A second is under negotiation but won’t...