Berlin risks running out of fuel unless German officials can find a way to keep a Cold War relic from falling victim to geopolitics. A refinery on the Polish border, which supplies the bulk of the jet fuel for the German capital’s airport and gasoline for the region’s vehicles, is caught up in the European Union’s standoff with Moscow over the war in Ukraine. A plan to ban Russian oil imports by the end of the year threatens to choke off supplies to the facility in the small town of Schwedt, which would cripple Berlin and much of eastern Germany in the process.