Document Type : Research Paper

Authors

• Hashem Dadashpoor ¹
• Mana Vahidbafandeh ²
• Mohammad Mehdi Panahi ³
• Maede Dadashpour ⁴

¹ professor of urban and regional planning, Faculty of Art and Architecture, Tarbiat Modares University,

² Ph.D Candidate, Department of Urban Planning and Design, Faculty of Art and Architecture, Tarbiat Modares University, Tehran, Iran

³ PhD Candidate in Urban Planning, Urban Planning Department, Faculty of Urban Planning, Faculty of Fine Arts, University of Tehran, Tehran, Iran.0009-0003-2590-1833

⁴ Master's student in Architecture, Faculty of Urban Planning, Faculty of Fine Arts, University of Tehran, Tehran, Iran.

Abstract

In recent decades, the role of cities within the global governance system has undergone a significant transformation, with cities evolving from purely administrative units to active actors in transnational interactions. This transformation, referred to in the literature as “urban diplomacy,” enables cities to act independently or semi-independently through intercity networks, thematic collaborations, and city-to-city relations. Among these, sister city relationships—one of the oldest yet most contested mechanisms of urban diplomacy—have oscillated between symbolic functions and practical collaborative capacities. Despite the expansion of research in this area, the existing literature remains largely fragmented, heterogeneous, and lacking a coherent analytical synthesis regarding the dimensions, functions, and real limitations of this mechanism. The aim of this study is to provide a systematic overview of the conceptual and functional developments in urban diplomacy, with a focus on sister city mechanisms, identifying dominant patterns, research gaps, and policy implications. To this end, a systematic review methodology was employed, and scientific articles published between 2000 and 2025 in reputable citation databases were searched, screened, and analyzed. Extracted data were coded and categorized using a thematic analysis approach, and dominant themes were identified. The findings indicate that contemporary urban diplomacy is transitioning from symbolic and ceremonial approaches toward problem-oriented, networked, and learning-based collaborations. Sister city relationships can be explained through five core components: multi-level governance and institutional legitimacy; decision-making rationality and collaboration leadership; institutionalized implementation and economic sustainability; networked and innovative empowerment; and learning, resilience, and data-driven evaluation. At the same time, results show that in the absence of clear institutional frameworks, the capacities of sister city relationships are often reduced to symbolic interactions, preventing the achievement of sustainable outcomes. Accordingly, this study emphasizes the necessity of redefining sister city relationships as a selective, problem-oriented, and institutionally capacity-based mechanism and provides an analytical foundation for more informed policy-making in urban diplomacy and the management of cities’ transnational interactions.

Keywords

• Urban diplomacy
• sister city relationships
• international urban networks
• multi-level governance
• problem-oriented collaborations

Main Subjects

• Urban Planning