The 'integration' of infrastructures has emerged as a central discourse in how future technical networks should be designed, delivered and managed to cope with the challenges of urbanisation and climate change. However, just how a nation state or an urban region can achieve this 'integration' is unclear. Infrastructural networks differ greatly across regions, nation states and continents, and the differences in how these networks are governed and structured is often overlooked. This paper is an attempt to kick-start a discussion on the meanings and implications of infrastructure integration and to examine how it may occur in practice. The paper has two broad objectives. First, to examine the features of infrastructure integration and to categorise theoretical definitions into five forms -organisational, technological, sectoral, geographic and social. Second, to link academic discussions on infrastructural futures to longstanding debates on the institutional and regulatory variations between nations. This paper examines the institutional differences of three Western countries -the United States, the United Kingdom, and Germany -and attempts to explore how variations in the concept of the state, relationships with cities, local authorities and citizens, and differing socio-economic cultures may influence and shape the potential for infrastructure integration.