The lesson of World War II is that "appeasement, concessions and weakness amount to a recipe for holocaust," Interim Prime Minister Ehud Olmert said Monday, as Israel paused to mark the start of Holocaust Remembrance Day and remember the 6 million murdered Jews. "Anti-Semitism, tyranny, lust for murder and terrorism have not passed forever," Olmert said. "Even today, they hang over the head of the free world like a sword of Damocles... "Only a determined and firm moral stand, only willingness to fight for and protect liberty will guarantee the future of humanity." In a direct reference to recent Iranian calls for Israel's annihilation, President Moshe Katsav said that the world must not ignore current calls for the destruction of the State of Israel. "I call on the Western world not to stand silently in the face of the nations that are trying to acquire nuclear weapons and preach the destruction of the State of Israel," Katsav said in his address at the annual state ceremony at Yad Vashem. "Hatred of Israel has not yet passed from the world, and it is thriving, mainly here on the soil of the Middle East, and is expressed through calls for the destruction of Israel. I call on the free world not to remain complacent in the face of such calls," Katsav added. The solemn Monday evening ceremony, which was broadcast live on television and radio, began with the lowering of the national flag in a sign of mourning. As a group of paratroopers stood at attention, elderly Holocaust survivors huddled with their families - many hand-in-hand with their grandchildren in military uniform - in the outdoor plaza on an unusually cold and windy April night. "In another generation, no survivors will be left as witnesses to the horror of the Holocaust, only the timeless records," Katsav concluded, referring to intensified efforts by Yad Vashem to collect testimony from all living survivors. The hour-long ceremony included a teenage orchestra, Hebrew songs, poetry readings and the traditional lighting of six torches. The official state wreath-laying ceremony will take place Tuesday morning at the Warsaw Ghetto Uprising memorial at Yad Vashem in the presence of Olmert and other VIPs. The "Unto Every Person There Is a Name" ceremony in which Holocaust victims' names are read out will follow at both the Hall of Remembrance at Yad Vashem and the Knesset. Approximately 250,000 survivors are thought to be living in the country. About one-third of them live in poverty, recent welfare reports have found.