German President Frank-Walter Steinmeier has called on Russian President Vladimir Putin to withdraw from Ukraine immediately. “Respect Ukraine’s sovereignty, stop the fighting,” Steinmeier appealed at the opening ceremony of the Catholic Convention in Stuttgart. “Mr Putin, end the suffering and destruction in Ukraine! Withdraw your troops! And do not refuse direct and serious talks with President [Volodymyr] Zelensky,” he said. Putin’s war is not only affecting the people in Ukraine. Because millions of tonnes of grain are being blocked in Ukrainian seaports, global grain prices have risen dra…