On August 19th 2003 the United Nations headquarters in Iraq at the Canal Hotel in Baghdad, was hit with a truck bomb. At least 22 people lost their lives in this attack, including the UN's top official in Iraq, Sergio Vieira de Mello.  In subsequent years, August 19th has been commemorated at the United Nations as World Humanitarian Day, in which the sacrifices of humanitarian workers are honored.    This year marks the 15th anniversary of the attacks on the UN headquarters in Iraq, which ushered an era in which the United Nations, and humanitarian workers more broadly, are more and more often the targets of terrorist violence.   On the line with me to discuss the 2003 bombing and its legacy today is Ambassador Elizabeth Cousens. She knew many of the victims of this attack, having worked with the UN in the middle east. She is a former top ranking official at the US mission to the United Nations and is now the deputy CEO of the United Nations Foundation.   We kick off discussing her experiences the day of the bombing and have a broader conversation about how this terrible event forever changed how the UN operates around the world.