
While cities generate economic activity, the security challenges they face expand and intensify as their populations rise. In 2016, there were 31 megacities-cities with more than 10m inhabitants. As rural residents head for the city in developing countries-which for purposes here we define as non-OECD countries, with the exception of Singapore-and wealthy global capitals draw in international talent, vast demographic shifts are creating cities with previously unimagined population sizes. In many respects it’s the very success of cities, in their role as global social and economic hubs, that makes them more vulnerable.

Dan Smith, director, Stockholm International Peace Research Institute.Ana Diez Roux, dean and professor of epidemiology, Dornsife School of Public Health, Drexel University.John Rossant, chairman, New Cities Foundation.Jacqueline Poh, chief executive office, GovTech Singapore.Michael O’Hanlon, senior fellow in Foreign Policy, Brookings Institution.Michael Nutter, professor of professional practice in urban and public affairs, Columbia University.Brian Nussbaum, assistant professor, Department of Public Administration and Policy, Rockefeller College of Public Affairs, State University of New York at Albany.Robert Muggah, co-founder, Igarapé Institute.Mitchell Moss, professor of urban policy and planning, and director, Rudin Center for Transportation, New York University.Dan Lewis, chief, Urban Risk Reduction Unit and head, City Resilience Profiling Programme, UN Habitat.Elizabeth Johnston, executive director, European Forum for Urban Security and executive director, French Forum for Urban Security.David Buck, senior fellow, public health and inequalities, The King’s Fund.Alan Brill, managing director, Kroll Cyber Security.Nathalie Alvarado, citizen security lead specialist, Inter-American Development Bank.Our thanks are due to the following people (listed alphabetically by surname) for their time and insights: Findings from the index were supplemented with wide-ranging research and in-depth interviews with experts in the field.
