The green economy is an economic development model that aims for sustainable growth, in which economic expansion, social welfare, and environmental protection are mutually reinforcing and implemented simultaneously (Isa et al., 2021, p. 94). This model emphasizes reducing green house gas emissions, promoting renewable energy, encouraging the conservation of natural resources, and strengthening recycling (Xuan et al., 2024, p.13). The Republic of Korea has been a pioneer in green-growth-oriented policies for more than a decade, viewing them as engines of growth and job creation based on “green technology and clean energy.” The Green New Deal initiative, launched in 2020, continues to promote the development of green infrastructure, low-carbon energy use, and innovation in green industries (Government of the Republic of Korea, 2020b, p. 13).

Cooperation between the ROK and ASEAN in the field of the green economy yields substantial benefits for both sides:

First, the green economy contributes to climate change mitigation and sustainable development. In the early decades of the twenty-first century, both Korea and ASEAN faced severe challenges posed by climate change. Their cooperation therefore aims to mitigate the impact of global warming, develop renewable energy sources such as wind and hydropower, and enhance energy efficiency and conservation. With its experience and advanced green growth technologies, Korea can support ASEAN in its transition toward a low-carbon, environmentally sustainable economy. The establishment of the ASEAN-Korea Director-Generallevel Dialogue on Environment and Climate Change in December 2020 marked an essential step toward strengthening policy and technical cooperation in such areas as air-pollution management, marine and forest conservation, circular-economy development, and climate-change response (Lee and Ro, 2021).

Second, the green economy fosters economic growth and creates opportunities for developing new sectors. It emphasizes the efficient use of natural resources, the reduction of greenhouse gas emissions, and the advancement of cleaner production models. This ensures that economic growth does not harm the environment, while minimizing the risks of natural disasters and resource degradation factors that could undermine long-term financial stability. Countries that invest in green-economy initiatives often achieve steady growth by optimizing production costs and improving productivity. For instance, the shift to renewable energy sources in place of fossil fuels not only reduces pollution but also decreases dependence on finite resources, thereby mitigating economic volatility caused by global energy-price fluctuations. The green economy also opens up new industries, generating employment and investment opportunities.

Third, the green economy enables the sharing of experience and capacity building for sustainable economic development. Since implementing its “Green Growth” strategy in 2008, Korea has been well-positioned to share practical models and policy lessons with ASEAN (Oh and Gil, 2024), particularly in clean technology development and resource optimization. South Korea has successfully transitioned from a landfill-dependent system to a “resource-circulating society”. Key technologies transferred include advanced material sorting machines, landfill gas management, and incineration with energy recovery (Lee and Cha, 2020, p.8). These experiences have been effectively transferred through key bilateral and multilateral initiatives, such as the Korea-ASEAN Environmental Cooperation and Sustainable Development Initiative. Through such programs, ASEAN gains access to advanced green development models, improved environmental management capacity, and enhanced expertise in renewable energy and digital transformation for sustainable production. This cooperation strengthens human resource development while linking Korea’s technological capacity with ASEAN’s sustainability needs, laying the foundation for joint growth and accelerating the region’s energy transition (Hong, 2021).

During the early decades of the twenty-first century, successive administrations of the Republic of Korea have shown a clear evolution in their policies toward ASEAN in the green economy, from broad strategic rhetoric to more tangible, action-oriented cooperation. From a Historical Institutionalist perspective, the Lee Myung-bak era represents a critical juncture where the “Low Carbon, Green Growth” vision established a new policy path. However, the empirical evidence suggests that while the domestic institutional framework was revolutionary, its externalization via environmental diplomacy remained “symbolic statecraft”. By analyzing the gap between domestic legislation and regional implementation, we observe that the early stages of Korea’s green diplomacy were constrained by institutional inertia, where diplomatic mechanisms had not yet caught up to domestic normative ambitions. This underscores the Historical Institutionalism premise that institutional change in foreign policy often lags behind domestic innovation due to existing diplomatic protocols. During President Park Geun-hye’s administration (2013– 2017), Korea maintained the same policy orientation. Still, it offered only limited technical support to ASEAN, focusing mainly on technology transfer and knowledge sharing without substantial financial or institutional engagement. A notable shift occurred under President Moon Jae-in (2017–2022), when the New Southern Policy (NSP) and its expanded version, NSP Plus, transformed green cooperation into a key pillar of Korea’s diplomacy toward ASEAN ( Table 1) For the first time, Seoul actively implemented sustainable development initiatives in renewable energy, waste management, and green human capital training. This period marked a transition from declaratory diplomacy to operational environmental partnerships, anchoring Korea’s green diplomacy with ASEAN through concrete projects and institutional collaboration.

During the presidency of Moon Jae-in, the New Southern Policy (NSP) was launched to diversify the Republic of Korea’s diplomatic and economic relations with ASEAN and India amid intensifying geopolitical competition between the United States and China (Lee and Ro, 2021, p.110). The NSP emphasized three pillars - People, Prosperity, and Peace, with a central focus on sustainable economic cooperation, including green-economy initiatives. In 2020, the policy was upgraded to NSP Plus, which introduced seven key initiatives, including a strategic orientation toward cooperation in future industries, reflecting Korea’s commitment to a green-economy partnership with ASEAN (Kim, 2023).

Under the frameworks of NSP and NSP Plus, Korea implemented and proposed a wide range of green-economy cooperation projects with ASEAN countries, focusing on two major areas:

First, cooperation in future industries and green technologies. NSP Plus identifies collaboration in future industries for shared prosperity as a top priority. This involves promoting joint efforts in the digital economy, renewable energy, and other green technologies. Leveraging its status as a global leader in the digital economy, Korea has established digital-cooperation platforms with ASEAN in information and communications technology (ICT), technology transfer, and joint RandD for future-oriented industries. Both sides agreed to establish joint centers for science and technology cooperation, standardization, and innovation, including the ASEAN-Korea Financial Cooperation Center (Lee and Ro, 2021, p.369).

Second, cooperation on the environment and climate change. Recognizing the urgency of global environmental challenges, both NSP and NSP Plus emphasize collaboration in environmental protection and climate change response (Peng Er, 2023, p.221). In 2020, Korea announced the Korean Green New Deal, which promotes the green transformation of infrastructure, the development of decentralized low-carbon energy systems, and innovation in green industries (Government of the Republic of Korea, 2020b, p.13). These strategies align closely with the green development plans of several ASEAN countries, providing a foundation for bilateral and multilateral cooperation. Joint efforts in water-resource management, biodiversity conservation, and addressing non-traditional security issues related to the environment have also been prioritized (Lee and Ro, 2021, p.264).

In the early decades of the twenty-first century, Southeast Asia, particularly ASEAN member states such as Vietnam, Indonesia, Thailand, and the Philippines, has been increasingly exposed to the severe impacts of climate change (Choi et al., 2021). The rising frequency and intensity of extreme weather events have inflicted profound economic, social, and ecological damage. Among the most vulnerable areas are Vietnam’s Mekong Delta and the Philippines, both highly susceptible to sea-level rise and environmental degradation. Within this context, transitioning from a linear to a green economic model has become an urgent imperative for the region (Arthur et al., 2022, p.28).

From the second decade of the century onward, the Republic of Korea intensified its cooperation on the green economy with ASEAN through renewable energy initiatives. The convergence between ASEAN countries’ growing demand for energy efficiency, particularly in Malaysia, Indonesia, Myanmar, and Thailand, and Korea’s Green New Deal initiatives has opened promising avenues for renewable energy collaboration and sustainable growth across the region (Choi et al., 2021, p.27).

In implementing environmental diplomacy toward ASEAN, the Republic of Korea has shifted its focus from a green growth model to green economy cooperation, as reflected in the expansion of policy frameworks, the upgrading of cooperative programs, and the increased provision of technical and financial assistance to ASEAN member states.

In terms of policy and strategic cooperation, ASEAN and Korea have jointly formulated several action plans to promote renewable energy as a pillar of regional sustainable development. The “ASEAN-ROK Plan of Action to Implement the Joint Declaration on the Strategic Partnership for Peace and Prosperity (2016–2020)” identifies several key priorities, including the development of renewable and hydropower energy, improvement of energy efficiency, enhancement of research and development (RandD) capacity, expansion of off-grid rural electrification systems, and advancement of modern power grid networks (ASEAN, 2012, p.8). This approach illustrates the increasingly close linkage between Korea’s green energy policies and ASEAN’s sustainable development strategy, thereby shaping an essential component of Korea’s environmental diplomacy.

In the field of technology transfer and capacity building, the Republic of Korea has strengthened its cooperation with ASEAN through technology transfer, professional exchanges, and RandD support to advance the energy transition process in the Mekong subregion. A notable example is the series of projects funded by the Mekong-Korea Cooperation Fund (MKCF), such as the Capacity-Building Program for Wind Energy Use for Sustainable Rural Development in Myanmar and assistance for the construction of hydropower plants in Laos (ASEAN, 2012, p.8). These activities not only contribute to the transfer of green technology and knowledge but also reaffirm Korea’s position as an active partner in promoting clean energy development across the region.

Regarding rural electrification, Korea has utilized its Official Development Assistance to support the Mekong subregion countries, particularly Laos and Myanmar, in expanding energy infrastructure and improving access to electricity. Within its Country Partnership Strategy with Laos, Korea financed projects to upgrade power transmission systems and develop electric grids, thereby helping the country move closer to its goal of nationwide electrification. In Myanmar, Korea has assisted in expanding energy infrastructure in remote areas and developing independent power supply systems. The “Mekong-Han River Declaration,” adopted at the 1st Mekong-ROK Summit in 2019, once again reaffirmed Korea’s role in advancing rural electrification through initiatives such as the Independent Energy Town Project (Hong, 2021, p. 15). In parallel, ASEAN and Korea have also cooperated on rural electrification programs using solar, biomass, biogas, mini-hydro, and off-grid energy sources (ASEAN, 2020, p. 6).

Specifically, Korea has implemented a range of initiatives to support renewable energy development, CO₂ emission reduction, and biodiversity conservation in Cambodia (Kang, 2022, p.47). Through the MKCF, additional wind energy projects for sustainable rural development have been implemented in Myanmar, while in Laos, the fund financed the establishment of an advanced hydrometeorological system for water resource management in the Mekong River Basin (Peng Er, 2023). Furthermore, Korea and ASEAN have expanded cooperation in green technology and digital transformation, thereby laying the groundwork for a comprehensive green economy model and promoting sustainable energy transition throughout the region (Kamaruddin and Deivasagayam, 2023).

After taking office in 2022, President Yoon Seok-yeol concretized cooperation with ASEAN in the field of green economy through three key measures: (1) the Korea-ASEAN Green Growth Initiative; (2) the K-SDGs (Korea Sustainable Development Goals) Initiative within the framework of the Indo-Pacific Strategy; and (3) the Korea-ASEAN Policy for Green Growth. These measures all aim toward sustainable development, yet they differ in characteristics, scope, and practical effectiveness. The Korea-ASEAN Green Growth Initiative, inherited and vigorously promoted by President Yoon Seok-yeol in 2022, is characterized by a clear focus and high degree of specificity, targeting renewable energy, resource conservation, and climate change adaptation.

With a clear strategic orientation, the initiative has generated several practical projects, such as cooperation in wind power development in Vietnam and the transfer of waste treatment technology in Indonesia, demonstrating short-term effectiveness from the outset. In contrast, the K-SDGs (Korea Sustainable Development Goals) Initiative under the Indo-Pacific Strategy is characterized by a long-term vision and a broad scope, encompassing not only environmental issues but also education, healthcare, economy, and energy. However, this diversity has also limited the initiative’s depth in each specific area, making it difficult to achieve rapid results—particularly given the challenge of coordinating interests among countries with different levels of development.

The Korea-ASEAN Policy for Green Growth can be viewed as a balanced synthesis of the two aforementioned initiatives, as it not only pursues green growth but also emphasizes support mechanisms for ASEAN through investment, technology transfer, and institutional capacity building. The policy’s effectiveness is reflected in its high adaptability to the diverse green development needs of individual ASEAN member states.

In contrast to the largely symbolic declarations of his predecessors, President Yoon Seok-yeol has demonstrated a far more tangible, operational level of support through a series of initiatives centered on technology transfer, financial assistance, and the establishment of specific cooperative mechanisms. In particular, joint programs on offshore wind energy, green hydrogen development, and renewable infrastructure construction in Vietnam, Indonesia, and the Philippines exemplify the high practical effectiveness of Korea’s current green economy policy.

As ASEAN continues to assume an increasingly strategic role within the regional architecture, Korea’s green economy development policy under President Yoon has strong potential to make constructive contributions. However, its long-term effectiveness remains to be evaluated, particularly with respect to implementation capacity and cooperation outcomes.

While President Moon Jae-in’s New Southern Policy (NSP) primarily focused on broadening partnerships and laying a policy foundation for green cooperation through dialogue and official development assistance, President Yoon Seok-yeol has decisively shifted toward concrete initiatives, institutionalized cooperation frameworks, and large-scale project implementation. The contrast in the depth and effectiveness of support between the two administrations underscores the increasingly substantive evolution of the Korea-ASEAN partnership in the green economy sector during the early decades of the twenty-first century, from policy formulation to practical realization.

The “Two-Tier ASEAN” Phenomenon and Absorptive Capacity A primary impediment to standardized regional cooperation is the profound structural heterogeneity among ASEAN Member States (AMS). Significant disparities in economic development have engendered an “absorptive capacity dilemma”, effectively bifurcating the region into two distinct tiers. High- and upper-middle-income economies, such as Singapore and Malaysia, function as “potential innovators”, possessing the requisite infrastructure to integrate Industry 4.0 technologies and advanced circular economy systems (Anbumozhi and Kojima, 2020). Conversely, the CLMV group (Cambodia, Laos, Myanmar, and Vietnam) continues to grapple with substantial development gaps, necessitating support for basic infrastructure rather than advanced technological interventions (Hong, 2024, p.93).

This bifurcation complicates South Korea’s strategic approach. High-tech solutions—such as smart grids or advanced waste-to-energy plants align well with the readiness of efficiency-seeking nations like Indonesia or Thailand, but are ill-suited for “latecomers” like Myanmar or Laos, which lack technological maturity. Consequently, disparities in digital infrastructure and labor skills have created a “structural bottleneck,” hindering the equitable distribution of green projects in South Korea. This creates a risk that aid will concentrate on more developed AMS, thereby ex acerbating regional inequality by leaving the least developed areas behind (Anbumozhi and Kojima, 2020).

A mutual path dependence on carbon-intensive industries challenges the credibility of Seoul’s environmental diplomacy. As a resource-poor nation, South Korea relies heavily on imported raw materials and fossil fuels to sustain key industries such as steel and semiconductors. Despite “Green Growth” rhetoric, South Korea’s industrial structure remains energy-intensive, and the nation has historically struggled to decouple from the “brown economy” model due to entrenched interest groups (Mathews, 2012).

Simultaneously, ASEAN economies prioritize rapid industrialization, a trajectory often correlated with rising CO₂ emissions and resource consumption. The regional energy sector is characterized by market distortions and fossil fuel subsidies, which retard the transition to sustainable energy mixes. In major economies like Indonesia and Vietnam, reliance on coal and the political complexities of phasing out thermal power generate resistance to South Korean renewable energy projects (Min and Cho, 2024). This mutual reliance on fossil fuel trajectories creates a “hypocrisy trap,” wherein bilateral cooperation is theoretically green but practically constrained by economic imperatives regarding energy security and industrial expansion (Mathews, 2012).

South Korea’s circular economy initiatives, particularly those involving automated recycling and waste management technologies, risk inducing socio-economic friction with ASEAN’s informal sector. In emerging Asian economies, the informal sector is integral to waste management, handling approximately 95% of e-waste recycling in Vietnam and processing 700,000 tons of plastic annually in Indonesia (Arthur et al., 2022, p.101). These informal laborers often operate without social safety nets and face significant health hazards. Introducing automated systems without addressing these socio-economic realities threatens to displace vulnerable populations, undermining the principles of a “Just Transition.”

A pronounced misalignment exists between the high-tech orientation of South Korean ODA and the “appropriate technology” needs of specific ASEAN communities. South Korea’s strategy leverages Industry 4.0 technologies: IoT, Big Data, and AI as drivers for the circular economy. While Singapore and Malaysia are positioned to adopt these solutions, less developed AMS struggle with fundamental waste management infrastructure, where low-cost, nature-based solutions may be more urgent (Anbumozhi and Kojima, 2020). Furthermore, the sustainability of technology transfer is often compromised by a lack of long-term capacity building. Projects frequently falter upon the conclusion of donor funding cycles because local skill bases in nations like Cambodia are insufficient to maintain advanced CE infrastructure (Ramli and Kasih, 2024, p.90).

South Korean Small and Medium-sized Enterprises in the green sector face elevated risks when entering the ASEAN market. The “medium risk, medium return” profile of green projects creates a “financing air pocket,” making capital mobilization significantly more difficult for SMEs compared to large conglomerates. Additionally, the scarcity of financial guarantees and insurance for private green investment impedes the scaling of South Korean private-sector participation. Without innovative de-risking mechanisms, South Korean green technology firms will remain hesitant to invest in environmental public goods where returns are ambiguous or dependent on inconsistent local regulatory enforcement (Moon et al., 2022, p.10).

In the context of environmental diplomacy in Southeast Asia, South Korea faces intense competition from established incumbents. Japan, through JICA and long-standing environmental networks, has cultivated deep regulatory affinity and institutional linkages with AMS, particularly in waste management and technical standards. Simultaneously, the EU exerts influence through normative power, using mechanisms such as the Carbon Border Adjustment Mechanism and strict circular-economy standards to compel ASEAN nations to adjust their export policies (Arthur et al., 2022, pp. 18–19). China is aggressively promoting the Belt and Road Initiative with massive financial commitments for infrastructure, including energy and waste treatment. Despite criticism regarding debt traps and environmental impacts, the sheer scale of Chinese capital remains highly attractive to infrastructure-hungry nations like Laos and Cambodia (Ramadhan, 2019). South Korea, possessing more modest financial resources, struggles to compete directly on the scale of aid.

The robust presence of these partners poses a significant challenge for South Korea in establishing a distinct identity for its “Green Growth” or “New Southern Policy” initiatives. Although Seoul attempts to present its model as an industrial development strategy rather than solely as environmental protection, the strategic overlap makes its initiatives susceptible to being overshadowed or perceived as derivative of Japanese and Western models. Furthermore, ASEAN’s “hedging” strategy, wherein member states accept aid from multiple sources to maximize benefits without committing to a single set of technical standards, dilutes the strategic impact of Seoul’s environmental diplomacy.