Urban Diplomacy: History, Developments, and Benefits

Urban diplomacy refers to the activities and relationships among cities and other subnational entities aimed at achieving political, economic, and cultural objectives. Throughout history, cities have consistently served as significant centers for political exchange and interaction, often acting as mediators in conflicts between parties. However, the emergence of urban diplomacy in its modern sense can largely be traced to the mid-20th century. The first generation of this modern diplomacy was based on formal bilateral relationships (often sister cities), centered around cultural, economic, and humanitarian issues. For instance, sister-city programs following World War II, along with the establishment of organizations like Sister Cities International in 1956, strengthened cultural connections and people-to-people exchanges among major cities.

In the late 20th century and early 21st century, as global concerns such as climate change, migration, and sustainable development grew, urban diplomacy expanded and became more structured. From the 1970s, the concept of “paradiplomacy” (parallel diplomacy) emerged to describe the external activities of local governments. Gradually, inter-city networks focused on specific issues were formed; estimates suggest that approximately 300 urban networks have been active worldwide in recent years. These networks are each centered on a specific theme: for example, the C40 network assists city leaders in reducing greenhouse gas emissions, the Global Resilient Cities Network focuses on resilience against crises, and the Mayors Migration Council addresses urban migration. International organizations have also taken note of this evolution; for instance, UNESCO promotes cooperation among cities through its Creative Cities Network, emphasizing creativity and culture as drivers of sustainable development. Currently, institutions such as UN-Habitat and UN climate conferences have incorporated urban diplomacy into their agendas, increasing city participation in global frameworks (including the Sustainable Development Goals and climate agreements). Overall, cities now view themselves as active players on the international stage, engaging increasingly in global issues such as climate, migration, and urban development, parallel to national policies.

Key Actors and Inter-City Networks
In recent decades, several categories of actors have emerged prominently in urban diplomacy. First, inter-city networks like United Cities and Local Governments (UCLG) serve as forums for exchanging perspectives and providing training among cities. Additionally, thematic coalitions such as C40 (a network of 100 major city mayors for climate action), ICLEI (International Council for Local Environmental Initiatives), the Resilient Cities Network, and the Mayors Migration Council are among the most significant entities that systematically pursue joint urban projects. Other groups are active at continental or regional levels, such as the Latin American city unions (Mercociudades and UCCI) and the Association of Mayors of Special Economic Zones.

The second category comprises leading global cities. Cities such as New York, London, Paris, Tehran, Munich, Buenos Aires, Tokyo, and others, leveraging their large populations, strong economies, and robust infrastructure, have established representative offices, economic consulates, cultural programs, or innovation centers in other countries. These cities, in addition to their network memberships, strengthen their role in international decision-making through “mayors’ summits,” global conferences, and economic missions.

Alongside these, global and international institutions also involve cities in decision-making processes. For example, the United Nations Human Settlements Programme (UN-Habitat), UNESCO, the World Health Organization, and other UN specialized agencies advance urban-focused policies in areas such as culture, health, and disaster response. In recent years, new international initiatives like the “U20” (a forum for cities of G20 countries) have been launched, where mayors of G20 member cities convene to contribute to shaping global agendas.

Benefits of Urban Diplomacy
Urban diplomacy is a powerful tool for improving cities’ conditions across various domains:

• Economic Development: Inter-city cooperation and partnerships can create commercial and investment opportunities. Research indicates that sister-city networks and other urban agreements play a significant role in economic prosperity. For example, according to a report by Sister Cities International in the United States, the network’s activities contributed over $525 million directly to the U.S. economy in 2015. This figure includes spending by incoming tourists and business events, with foreign guests’ travel costs (exchange visitors) amounting to approximately $63.7 million and revenue from hosted events exceeding $56.5 million. Global calculations also show that this network directly contributed about $237 million and, factoring in the purchasing power parity (PPP) effect, over $18.5 billion to the world economy. Thus, urban diplomacy can drive cities’ economic development by attracting tourists, encouraging product exports, and implementing joint projects.
• Enhancing Urban Brand and Identity: International city relationships help strengthen their global identity and reputation. In urban diplomacy, cities strive to highlight their cultural, historical, or innovative distinctiveness. For instance, participation in programs like UNESCO’s Creative Cities Network provides networking opportunities with other cities, enabling cities to position themselves as hubs of creativity (e.g., in film, music, or design). This global positioning strengthens the city’s brand, aiding in attracting cultural investors, students, and tourists. Hosting joint cultural festivals (within sister-city frameworks or international summits) elevates cities’ visibility to global audiences, creating positive differentiation.
• Environmental and Cultural Cooperation: Many contemporary challenges are transnational and translocal, such as climate change and the need for environmental preservation. Cities can leverage urban diplomacy to propose collective solutions. Networks like C40 are explicitly dedicated to exchanging climate-related experiences among mayors. In 2020, a C40 publication noted that the network unites a group of leading mayors committed to addressing the climate crisis. Through this synergy, cities can accelerate measures for carbon emission reduction, clean transportation, or green infrastructure by learning from one another. Cultural exchanges, such as joint artistic and educational events and interactions with diaspora communities, enhance cultural convergence and mutual understanding among cities; for example, sister-city municipalities often collaborate in organizing exhibitions, artist exchanges, and student partnerships.
• Attracting Investment and Tourism: Urban diplomacy provides an effective platform for showcasing cities’ investment potential and tourist attractions. By establishing long-term relationships with foreign cities and organizations, cities can attract new tourists and familiarize international investors with their business opportunities. For instance, results from the U.S. sister-city network demonstrate that inter-city exchange programs significantly boosted tourist inflows, created hundreds of jobs, and injected substantial tax revenue into the national economy. In summary, urban diplomacy enhances a city’s international recognition, which in turn drives tourism and investment.
• Expanding Cooperation Networks and Experience Sharing: One of the most significant benefits of urban diplomacy is access to global knowledge and experiences. Through membership in urban networks and participation in international gatherings (such as mayors’ summits or Urban20), urban managers can discuss shared challenges with their counterparts. Research shows that inter-city collaborations are grounded in practical, problem-solving approaches, with cities bypassing geopolitical interests to exchange actionable solutions. A notable example of this experience sharing is the creation of joint platforms during crises; for instance, during the COVID-19 pandemic, a coalition of organizations like UCLG and UN-Habitat launched the “Beyond the Crisis” platform to enable urban policymakers to share successful strategies. Initiatives like U20 also ensure that cities’ voices are heard in high-level global negotiations (G20). Consequently, inter-city networking allows cities to enhance their urban science capacities, benefit from other cities’ experiences, and implement innovative solutions in their urban practices.

Thus, urban diplomacy is an operational and effective tool for municipalities and urban managers. Through strategic planning to establish overseas representative offices, participate in inter-city networks, and utilize global platforms, cities can more effectively achieve their developmental goals in economic, social, and environmental domains. International studies and reports have also underscored the importance of this approach and the opportunities cities gain from transnational interactions.