On 7 November 2012 Michel Geertse defended his dissertation Defining the universal city. The International Federation for Housing and Town Planning and Transnational Planning Dialogue 1913-1945, Amsterdam 2012.

Twentieth century urban planning has often been labeled as international. Ideas, concepts (like Garden City, City Beautiful, Linear City), plans (on a local, regional or national scale) and experiences circulated, were imitated and innovated. Planning historians use concepts such as artistic inspiration and Schumpeter’s innovation theory to explain the international traffic of planning theory and experience. However, they hardly pay attention to the international networks that are necessary to disseminate urban planning thought. The international discourse was not just defined by inspirational and innovative contributions, but was also heavily influenced by the way an extensive international network and planning society (or Urban International) embedded policies, negotiations and exchange.

The existence of a typical Urban International network for the dissemination of ideas was the primary factor responsible for the production of international urban planning thought during the first half of the 20th century.

The Urban International is aptly analysed in recent literature by historians with an interest in local governance. Despite the fact that we know a lot about it today, relatively little is known of its individual constituents. Among these the International Federation for Housing and Town planning (IFHTP), a pivotal player in the Urban International, has been properly studied in this dissertation for the first time.

The dissertation reconstructs the history of this largely forgotten organisation. The fate of the Federation demonstrates how the Urban International operated on the micro level of the single network organisation. Presupposing that the Urban International was not a neutral agent, the dissertation analyses how the IFHTP effected and affected the international urban planning discourse.

The study of the IFHTP is a fascinating subject in itself, but it is also very helpful for the study of Urban Nebula, even though the planning of airports never was very prominent in their meetings. Nevertheless the worldwide internationalisation of the Urban International  after World War II - including its network, planning discourse and planning concepts - has a parallel in the globalisation of air traffic and the transformation of the airport.