FRANKFURT—Volkswagen AG, Europe’s top carmaker, doubled its operating profit in 2021 but warned that Russia’s invasion of Ukraine and its impact on supply chains could hit business this year in unforeseen ways. Carmakers are scrambling to find alternative sources of vital parts made in Ukraine, including wire harnesses, from as far afield as China and Mexico, as Russia’s invasion halts assembly lines and breaks complex supply chains. “The conflict … has an impact on the entire global economy, on raw materials, on supply chains and therefore on our company,” Volkswagen finance chief Arno Antlitz told journalists on Friday after publishing preliminary 2021 results. “The impact of this cannot be conclusively assessed at this point in time,” he said, adding the group was currently working on tapping other suppliers in Eastern Europe and North Africa to obtain wire harnesses. Volkswagen said there was a risk that the latest developments in the …