Since the establishment of the diplomatic ties in 1992, South Korea and China have come to form one-day-travel zone and mutually reliant economic relationship within the short time frame. The number of visitors to and from both countries increased approximately 34 fold from 375,000 in 1994 to 12.84 million in 2016 and the trade volume increased roughly 38 fold from 6.4 billion dollars in 1992 to 241.5 billion in 2020. Exchanges and cooperation in all walks of life between the two countries became very vibrant, as there were 47 summits from 1992 to 2019 and 40 high level meetings at or above prime ministerial levels. From October 1991 to April 2021, a total of 129 foreign ministerial meetings took place, an indication that there were dialogues at a working level. Apart from exchanges at central government, regional governments also actively engaged in exchanges. As of late 2020, a total of 672 sister and friendly city deals were signed between cities in the two countries, accounting for roughly 41.5% of the total deals signed since 1993. Thanks to close engagement between the two countries, the bilateral relationship has developed into a “partnership” in 1998 to be upgraded as “strategic partnership” a decade later.

However, there has been continued criticism that “the approach of seeking common ground while maintaining differences (or liberalism-based approach)” served as a setback to the bilateral relation for the last 3 decades. What's worse is that changes in external structure, such as standoff between the U.S. and China and North Korean nuclear issue undermined the relations before they deepened. Amid a series of crises, ranging from the sinking of a South Korean naval ship, Cheonan, a shooting on the island of Yeonpyeong, North Korea's 4th nuclear test to the failure to set up a hotline between leaders of two Koreas, South Korea and China recognized that the two countries have very different strategic perception on issues related to the Korean Peninsula.

Through the THAAD deployment issue, it is confirmed that South Korea-China relations have already been subordinated to U.S.-China relations. The "strategic dilemma" situation in which South Korea is forced to choose between the U.S. and China has become a reality. Furthermore, due to China's assertive diplomatic policy based on its economic power and competition for technology hegemony between the U.S. and China, high economic interdependence between South Korea and China has become a big burden. Economic cooperation, a main driver behind the establishment of diplomatic ties between Seoul and Beijing became a "political tool", thanks to China's economic retaliation and Washington and Beijing's competition over the latest technologies. In socio-cultural fields, strong nationalism sentiment in both South Korea and China is fueling conflicts, rather than serving as a catalyst for cooperation based on historical and cultural similarities. As a result, South Koreans' image of China continues to deteriorate.

Seoul’s international cooperation with China has grown in line with rapidly progressing relations between South Korea and China. The City focused on capital diplomacy upon signing a sister city deal with Beijing in 1993 continued to establish friendly city deals with cities in China’s economically advanced eastern coastal region, which is geographically close to South Korea. From 2014, Seoul expanded exchanges and cooperation into China’s cities in landlock regions. In the process, Seoul attempted “institutionalization”, by setting up Seoul-Beijing Joint Committee based on its exchanges and cooperation with Beijing. However, there are limits as Seoul has focused only on bilateral diplomacy with Beijing due to the lack of mid to long-term urban diplomacy strategies and policy tailored to China. Specifically, there has been neither substantial cooperation with sister cities in China nor bilateral diplomacy through international organizations among cities, which is an emerging trend in urban diplomacy. In addition, there are no strategic planning and implementation from broader perspective even urban diplomacy is affected by South Korea-China relations, not to mention China-U.S. relations and other international relationships.

The year 2022 marks 30th anniversary of the establishment of diplomatic relations between South Korea and China, but the two stands at a crossroads of conflicts and cooperation. As the bilateral relations have rapidly grown, there are countless unresolved issues. It is true that global situations are not favorable to the bilateral diplomacy compared to 30years ago. Based on the critical assessment of South Korea-China relations mentioned above, a step-by-step approach, which are described below to substantiate the bonds while minimizing possible tensions need to be considered and, in the process, Seoul City is required to seek its roles taking account of the nature or urban diplomacy. To start off, the two countries together need to find a crisis management measure at the national level against issues that could escalate into conflict. In the short and midterm, the two need to practically improve images of the other by implementing public diplomacy based on precise diagnosis rather than marketing. At the same time, regularize exchanges at different levels, such as at central government, regional government and private sector between two countries and create governance, which can ensure synergy effect of such exchanges between the two. In the mid to long-term, pursue a "problem-solving-oriented" relationship between the two.

As the capital, Seoul City needs to check, but cooperate with the central government’s diplomacy toward China while at the same time, implementing the following strategies and policy that are in line with nature of urban diplomacy. First, it should proactively push for international organization-based bilateral diplomacy between cities. In short, it is combining activity for international organizations with bilateral diplomacy as part of multilateralism strategies. Second, as regionalization strategies, it should establish objectives and agendas of exchanges with individual regions in China which go beyond city-to-city exchanges and cooperation. Third, it should enhance efficiency in exchanges and cooperation and secure exchange platforms between friendly cities by setting up “Seoul-China sister and friendly city diplomatic meeting (tentative)”. Fourth, it should build database on the individual regions, cities and sectors to help set up policy and make detailed policy based on it. Along with this, it should strengthen China team for comprehensive urban diplomacy toward China and systemize exchange meetings between officials in Seoul and their counterparts in China. Lastly, to promote exchanges and cooperation at working level, it should establish online and offline discussion system.