“Think globally, act locally.’’ This isn’t just a slogan. It’s a deep conviction shared by a growing number of elected officials, experts and citizens around the world: Cities — especially the large ones — can and must play a leading role in solving the complex problems of our time. This new mission is driven by growing urbanization, which is happening world-wide; more than half of the world’s population now lives in urban areas.

Global trends will bring to the fore cities and city governments as the new actors in international relations and diplomacy. Those trends are: the increasing urgency of urban development and the globalization of cities.