Peacekeeping has proven to be one of the most effective tools the United Nations uses to maintain international peace and security throughout the world. UN Peacekeepers provide security and the political and peacebuilding support to help countries make the difficult, early transition from conflict to peace. Today is a day to pay tribute to all the men and women who have served and continue to serve in United Nations peacekeeping operations for their professionalism, dedication and courage, and to honour the memory of those who have lost their lives in the cause of peace.