U.S. Defense Secretary Lloyd Austin on Saturday cheered Ukraine’s capture of the key bastion of Lyman from Russia in eastern Ukraine, saying it was an encouraging battlefield success that would create new dilemmas for Russia’s military. “Absolutely, it’s significant. We’re very encouraged by what we’re seeing right now,” Austin told reporters at a news conference in Hawaii. Russia had used Lyman as a logistics and transport hub for its operations in the north of the Donetsk region. Its capture is Ukraine’s biggest battlefield gain since a lightning counteroffensive in the northeastern Kharkiv …