The Internet revolution has empowered individuals to access all kinds of information and make informed decisions. In this process, non-state actors without physical territory have participated in economic, cultural and political globalization. These non-state actors have broken the monopoly of national government on diplomacy.

As of 2015, global urbanization rate was 54%. More than half of the total population in the world now live in cities. Thus, problems that cities are facing are also global problems. Many studies have suggested that cities should lead the way in solving global problems. In fact, global problems such as climate change, terrorism, security, immigration and environmental degradation will hurt city residents the most. Since there is only a fine line between urban and global problems, some argue that the role of cities is getting more and more important. How global cities act has the utmost importance. Indeed, global city such as Seoul has strong influence on global matters.

Thus far, the Seoul Metropolitan Government (SMG) has produced positive outcomes from its activities in international cities networks such as CityNet, WeGO and C40. Through such international cities networks, the SMG has shared its innovative policies and strengthened global networks. However, city diplomacy efforts of the SMG have been limited to sharing policies, interchanges of staffs, cultural exchanges and promoting tourism. In other words, Seoul’s city diplomacy has been largely a software diplomacy. However, unpredictable international situations including the U.S.-China trade dispute, conflict over the South China Sea and Brexit do not allow the SMG to stay in the comfort zone of “easy diplomacy”. The rapidly changing world demands SMG to perform a substantive role in diplomacy. Indeed, cities in European countries or the United States often play a significant part for peace-building in destroyed cities after war or regional conflict is over. In other cases, cities have proposed advanced solutions to chronic global problems unresolved with the diplomatic efforts between nations.

These cases suggest that there are potential or fresh possibilities that city diplomacy can contribute to the world. Specifically, the following three types of city diplomacy activities have significant impact: 1) sharing policies through international cities network, 2) contributing to peace-building effort and 3) exporting advanced urban solutions to other cities. By reviewing numerous case studies representing these types of diplomatic activities, this study draws policy implication for the SMG. In summary, Seoul needs a city diplomacy strategy to provide understanding of what the city’s diplomatic assets are, what the city can do with city diplomatic efforts and what direction the city should be headed. Through such strategy, SMG can play a role in the diplomatic arena.