S. Korea Considers CPTPP Membership: Nations should Work to Strengthen Breakwater against Protectionism

Editorial

14:02 JST, September 16, 2025

The global free trade framework is facing a crisis due to the high tariff measures taken by the United States. It is hoped that the number of member countries of the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP) will increase to reinforce its function as a breakwater against protectionism.

The South Korean government has announced its policy to consider joining the CPTPP. This is because South Korea judged it necessary to expand overseas sales channels out of concern for a possible decline in its exports due to the high tariff measures of U.S. President Donald Trump’s administration.

The CPTPP, in which Japan plays the leading role, currently includes 12 countries, such as Australia, Britain and Vietnam. From now, South Korea intends to proceed with coordinating the interests of relevant parties and submit an application for entry. If approved by all member countries, Seoul will become a CPTPP member.

To deal with the high tariff measures that have been imposed one after another under the “America First” policy, the best step for countries and regions that wish to protect free trade, such as Japan and Europe, is to open their markets to each other and pursue growth by invigorating trade.

The CPTPP is a massive free trade bloc that accounts for about 15% of the world’s total gross domestic product. South Korea is a middle power with an economy on a scale second to that of the Group of Seven advanced nations. Should it join the CPTPP, it is expected to strengthen the free trade framework.

The CPTPP is an agreement that achieved an extremely high level of liberalization by eliminating nearly 100% of tariffs on imports and also establishing the protection of intellectual property rights and the promotion of data distribution, among other rules. The European Union has also expressed its intention to cooperate with CPTPP countries.

Expanding CPTPP membership could also have the effect of serving as a check on the Trump administration, which disregards rules.

South Korea had previously indicated its policy of applying for CPTPP membership in 2021 during the administration of then President Moon Jae-in. However, discussions stalled due to opposition from agricultural groups and other entities to tariff elimination and the deterioration of Japan-South Korea relations stemming from the Moon administration’s anti-Japan stance.

Since then, Japan-South Korea relations significantly improved under the administration of former South Korean President Yoon Suk Yeol. Current President Lee Jae Myung has also expressed his intention to build a future-oriented relationship with Japan.

If this trend of improvement in Japan-South Korea relations continues, Japan could potentially support South Korea’s joining the CPTPP. The security environment in Northeast Asia is growing more severe than ever. Deepening economic ties between Japan and South Korea would also be beneficial for strengthening bilateral defense cooperation.

However, there remains an issue Japan cannot overlook.

This is South Korea’s ban on imports of seafood from eight prefectures, including Fukushima, which has been in place since September 2013 after the 2011 Great East Japan Earthquake. While 55 countries and regions introduced restrictions following the nuclear accident, most have since lifted them. Only four countries and regions, including China and South Korea, still maintain import restrictions.

Japan and South Korea need to engage in discussions and link them to lifting this import ban.

(From The Yomiuri Shimbun, Sept. 15, 2025)