Introduction

In December 2022, South Korea revealed its own Indo-Pacific strategy, called “Strategy for a Free, Peaceful and Prosperous Indo-Pacific Region.”[1] Closely echoing the overall vision of the latest US version, South Korea’s Indo-Pacific strategy signaled a decisive shift in its approach to the Indo-Pacific, from the former administration’s “strategic ambiguity” to one that is more clearly aligned with the US intent to contain China. For decades, Seoul has maintained a delicate balance between the two great powers, the US and China, so that it can ensure security assurance from the US and benefit from its economic dependence on China – hence the name strategic ambiguity. With an evolving North Korean nuclear threat and the ongoing US-China strategic competition, however, Seoul has now opted for a position of “strategic clarity” which emphasizes South Korea’s more active role in the Indo-Pacific as a participant of the US-led extended deterrence strategy, with a greater significance placed on the US-South Korea-Japan trilateral security cooperation. In evaluating the current challenges a s well as anticipated benefits of South Korea’s ambition to be a “pivotal state” in the Indo-Pacific with its groundbreaking security policy shift, this article aims to provide justifications for its newfound emphasis on the US-South Korea-Japan trilateral security cooperation.

Current Challenges of Strategic Clarity

Despite their shared security concerns in the Indo-Pacific vis-à-vis North Korea, South Korea and Japan throughout the years have had a strained relationship due to some unresolved historical concerns between them. Naturally, according to Professor Yoichiro Sato, Dean of College of Asia Pacific Studies at Ritsumeikan Asia Pacific University and an expert analyst of security in the Indo-Pacific, “the greatest challenge now for a strengthened US-Japan-South Korea trilateral security cooperation is the deterioration of the Japan-South Korea relations.”[2] In particular, relations between the two countries dropped to their lowest point in decades after South Korean courts in 2018 ordered that two Japanese companies pay compensation for wartime forced labor. The Japanese government refused to comply with the South Korean rulings, arguing that “all compensation issues were resolved under the 1965 basic treaty which included a payment of $500 million from Tokyo to Seoul to cover all compensation stemming from historical issues.”[3] The South Korean rulings, which were backed by then South Korean president Moon Jae-in, reignited the historical feud between South Korea and Japan; following Japan’s imposition of export controls on South Korea on the grounds of national security concerns in 2019, South Korea responded by not renewing the General Security of Military Information Agreement (GSOMIA) with Japan, effectively suspending all US-South Korea-Japan trilateral security cooperation and creating a “breakdown in communication in the air [and] sea space in the Indo-Pacific region actively patrolled by US forces.”[4]

While a complete dissolution of the GSOMIA between South Korea and Japan was prevented with a timely US intervention, Japan’s adoption of a “counterstrike” capability in its new national security strategy in 2022 is inviting new concerns from South Korea. From the Japanese perspective, the major break from its strictly self-defense-only postwar principle is in response to North Korea’s rapid progress with its nuclear program and China’s apparent ambitions in the Taiwan Strait. In essence, according to Professor Sato, the counterstrike capability is “strictly defense-oriented in nature”[5] and is an outcome of nearly ten years of debating by Japan’s ruling parties. With North Korea and China continuously developing new types of missiles, Japan’s current interceptor-reliant defense system is considered insufficient. On the South Korean side, some experts have advised the South Korean government to “discuss with Washington how the US can prevent Japan from executing an attack on North Korea without prior South Korean consent,”[6] so that Japan’s new counterstrike capability can be coordinated with South Korea’s own preemptive strike, or the “Kill Chain” defense system. Without a close coordination, Japan’s new counterstrike capability may become an additional obstacle for South Korea’s strategic clarity for a strengthened US-South Korea-Japan trilateral security cooperation in the Indo-Pacific.

Justifications for Strategic Clarity

With the current Yoon Suk-yeol administration of South Korea and Japan actively seeking “mutually acceptable mechanisms”[7] to resolve the thorny issues between the two countries, it is essential to investigate some of the most anticipated benefits for South Korea’s strategic clarity, assuming an expedient progress on the ongoing South Korea-Japan rapprochement. With an improved intelligence sharing between South Korea and Japan pledged as part of a joint statement with the US in November 2022, South Korea’s strategic clarity for a strengthened trilateral security cooperation with the US and Japan can “detect and assess the threat posed by incoming [North Korean] missiles, [achieving] a major step for deterrence and stability”[8] in the Indo-Pacific. While Japan’s new counterstrike capability caused some pushback in Seoul, the three countries’ real-time sharing of North Korean missile warning data as agreed in the joint statement would allow Seoul and Tokyo to coordinate their missile defense capabilities, thus more effectively deterring North Korean threat in the region. In the event of contingency on the Korean Peninsula, South Korea “will depend on rapidly deployed US military forces, but limitations in South Korean airfields, ports, and fuel availability require the US to use airfields and ports in Japan.”[9] Knowing this, North Korea may use “some nuclear weapons and missiles to coerce Japan into denying US access in a conflict, thereby preventing many US forces from being available”[10] in South Korea when needed. South Korea and Japan must accept that, “when it comes to North Korea, [their] fates are inextricably linked”[11] with each other, and their respective preemptive defense systems – South Korea’s “Kill Chain” and Japan’s new counterstrike capability – can apply effective deterrence pressure on North Korea only through a close coordination with the US. Indeed, Japanese destruction of even one North Korean nuclear weapon in the time of contingency can save at least tens of thousands of lives in South Korea, the same way South Korea’s Kill Chain can save tens of thousands of lives in Japan.

In addition to a greater extended deterrence pressure exerted on North Korea, South Korea’s strategic clarity for a strengthened trilateral security cooperation with the US and Japan could help South Korea become more aligned with the US Indo-Pacific strategy, enabling it to cooperate with other countries more actively on many functional issues, “ranging from health to climate change, supply chain, digital economy, cybersecurity, nonproliferation, counterterrorism, and others.”[12] Since the US’s Indo-Pacific strategy clearly stipulates “strengthening extended deterrence and coordination with our ROK and Japanese allies and pursuing the complete denuclearization of the Korean Peninsula”[13] as one of its security imperatives, South Korea’s more active participation in the trilateral security cooperation with the US and Japan has allowed it to establish proper institutional frameworks upon which the US, Japan, and other countries with shared interests and values cooperate to reinforce the rules-based international order. This is in stark contrast with South Korea’s previous Moon Jae-in administration, which sought strategic ambiguity between the US and China and had a “restrained voice and lack of connections to the institutional frameworks built among democracies, [with] South Korea’s confined diplomatic space and influence in the region.”[14] With an evolving North Korean nuclear threat, South Korea’s strengthened three-way security coordination with the US and Japan and its clear alignment with the US Indo-Pacific strategy can allow for more robust partnerships in the region involving the US and Japan, which South Korea can join to “expand the horizon of its regional diplomacy”[15] and step up to the role of a “global pivotal state” that it envisions to become.

Conclusion

Some may question if the challenges of South Korea’s strategic clarity for an enhanced trilateral security cooperation with the US and Japan are too great to overcome for it to become a durable foreign policy doctrine. Fortunately, there is some substantial progress which South Korea’s Yoon administration has taken the initiative to repair the damage done to the US-South Korea-Japan trilateral cooperation. For examples, to swiftly resolve the forced wartime labor compensation issue, South Korea proposed creating a domestic fund to compensate the victims in January 2023; to reinforce intelligence sharing between Seoul and Tokyo, South Korea has publicly announced its plan to completely normalize GSOMIA in June 2022; to expand military cooperation with the US and Japan, South Korea has also conducted joint field exercises with the US and Japan in November 2022 to respond to North Korean threat. While more can be done, South Korea’s aspiration to become a regional and global leader alongside the US and Japan as a pivotal state in the Indo-Pacific is evident, and a growing North Korean threat and the intensifying US-China competition provide unmistakable justifications for South Korea’s strategic clarity, which aims to advance “freedom, peace, and prosperity through liberal democratic values and cooperation”[16] in the region along with the US and Japan.

Author Biography:

Mr. Euihyun Kwon is an MA International Commerce student at Korea University, Republic of Korea. He has a BA degree in Economics from University of California, San Diego, where he graduated cum laude with honors. His area of focus is on ASEAN, US-China relations, and Indo-Pacific geopolitics.

References: