Japan and South Korea between shuttle diplomacy and energy diversification

On 19 May, Japanese Prime Minister Sanae Takaichi and South Korean President Lee Jae Myung met in Andong, South Korea, with the talks revealing a clear focus on strengthening bilateral relations and cooperation in the energy sector. This summit follows the one held in January 2026 in Nara and forms part of the broader framework of shuttle diplomacy, a series of meetings between the two leaders in each other’s hometowns, which carry great symbolic value and are aimed at restoring the historically turbulent relations between the two countries. In recent years, in fact, there has been a gradual rapprochement between Tokyo and Seoul, mediated by the Biden administration and partly driven by evolving global dynamics, notably the blockade of the Strait of Hormuz and the US’s gradual disengagement from the Pacific theatre.

Since the outbreak of hostilities pitting the United States and Israel against Iran, the crisis triggered in the Gulf has profoundly affected the two Asian countries, which, as far as fossil fuel supplies are concerned, depend almost entirely on imports. Among the major suppliers are the United Arab Emirates and Saudi Arabia, from which South Korea and Japan import approximately 45.81% and 82.79% of their crude oil, respectively. It is therefore no coincidence that the focus of the recent meeting was precisely the expansion of cooperation on supplies of crude oil and liquefied natural gas (LNG), both in terms of energy security and storage. In order to intensify this cooperation, the approach taken by Tokyo and Seoul appears to be based on two pillars: on the one hand, they aim to strengthen mutual energy security through trade in crude oil, petroleum products and LNG; on the other, they look to the entire Indo,Pacific region, promoting greater resilience in energy supply through the new Partnership on Wide Energy and Resources Resilience (POWERR Asia) framework, launched by Takaichi during the latest Asia Zero Emission Community (AZEC) Plus Online Summit on 15 April.

This is a project involving approximately $10 billion in funding from Japan in the form of loans, insurance and credit facilities for the economies of South,East Asia and the Pacific region, which are the most severely affected areas by the closure of the Strait of Hormuz. The plan is aimed at investing in measures and infrastructure capable of securing crude oil and derivatives in order to support the maintenance of supply chains during times of crisis and thus ensure long,term diversification and self,sufficiency. According to reports, the framework prioritises investment in alternative energy sources, such as LNG, biofuels, next,generation solar technologies and even nuclear energy, including small modular reactors.

Based on this information, it is therefore clear that, to tackle a crisis that does not currently appear likely to be resolved in the short term, South Korea and Japan are choosing to overcome historical differences, championing an approach of close cooperation, first bilateral and then regional, whose core remains the diversification of energy sources. This is because both countries have virtually no domestic production of fossil fuels, which, in a context such as the current one, makes the management of such reserves extremely complex in the medium and long term. In this context, it would therefore not be implausible to expect a scenario in which nuclear energy could also play a central role in the domestic energy mix of Seoul and Tokyo, already standing at 79% and 39.9% respectively in 2024, in order to replace fossil fuels. A hypothesis that would appear to be confirmed by the recent restart of 10 nuclear reactors across Japan in January 2026, such as the Kashiwazaki-Kariwa plant.