Background: The City of Calgary is a member of Mayors for Peace http://www.mayorsforpeace.org/english/index.html a network of more than 5,000 municipalities worldwide that oppose the targeting of cities by nuclear weapons and support the total elimination of nuclear weapons. Mayors for Peace is the leading international organization devoted to protecting cities from the scourge of war and mass destruction. Their Covenant gives the organization a mandate to work on a broad range of issues from the elimination of poverty to the protection of the environment. The 2020 Vision Campaign of Mayors for Peace aims for abolition of nuclear weapons by the year 2020. It has amplified the activities of the organization and fosters active participation of cities in one or more of its four programs which have a broad purview relevant to human security worldwide. Mayors for Peace is a brilliant and timely initiative, but if member cities do nothing more than “sign on,” there is a grave risk that the opportunity and the potential value of this initiative will be lost.