Dmitry Firtash, one of Ukraine’s richest men, was arrested last week in Austria on an FBI warrant. The natural gas oligarch has ties to the ousted government of Ukraine, Russia’s leaders and perhaps even Britain’s Conservative Party. And he has information that might help with sanctions against Russia.Dmitry Firtash, one of Ukraine’s richest men, was arrested last week in Austria on an FBI warrant. The natural gas oligarch has ties to the ousted government of Ukraine, Russia’s leaders and perhaps even Britain’s Conservative Party. And he has information that might help with sanctions against Russia.