At first glance, what strikes the reader about the articles that make up the collection for this special issue of Planning Theory is the diversity of the cases they examine. This observation raises obvious questions about their meaning for planning theory, questions that were raised by one audience member at the second panel at which the papers on which these articles are based were presented at the 2009 Association of Collegiate Schools of Planning Annual Meeting. What coherent themes, if any, emerge from these papers (in that session on Kabul, Bogota and New York) that were seemingly deliberately chosen to emphasize their difference? And what do we learn from these themes about planning theory?

In this article I argue that, particularly when all the articles are read together, they do indeed cohere strongly around the themes of urbanism and worlding–Roy’s (2010) term for the strategies and models of urban development aimed at enabling cities to enter global networks of economic exchange–that appear in the title of the collection, and that they make a significant contribution to planning theory. Each of the case studies presented here tells the story of the worlding efforts of planners in particular contexts–Kabul, New York, Bogota, and Santiago, as well as the case of Indian cities and the other examples mentioned in Roy’s framing article. In each case planners endeavor to reshape urban social, political, and cultural life and spatial relations to conform to an ideal of a globalized, cosmopolitan, economically integrated, and competitive city. This part of the story is familiar. The intriguing question is why such disparate strategies of worlding emerge in different locales. It is here that the idea of urbanism becomes important, for in each case there are other urbanisms at work, what I will refer to as actually existing urbanisms, that are rooted in alternative social dynamics (informality, violence, alternative cultural, and social visions, vote-bank politics), and that resist worlding practice. These existing urbanisms are manifest in a variety of appropriations of space and social