Germany's president Horst Köhler has stressed that his country must keep alive the memory of the horror of World War II unleashed by Nazi Germany for it to remain a reminder to future generations. "We have the responsibility to keep alive the memory of the agony and the its causes, and we must ensure that it never returns. There is no closure," Köhler said in a speech to a special meeting of the Bundestag, attended by the country's political leaders. He added: "We Germans remember with horror and shame the Second World War unleashed by Germany and the Holocaust, this breakdown in civilization, for which Germans are responsible. "And we remember the six million Jews who were killed with a fiendish energy." But Germans had every reason to be proud of their country's modern-day democratic reincarnation, the federal president added.