John Mearsheimer’s offensive realism theory argues that the anarchic structure of the international system pushes states into power competition and that great powers aim to establish regional hegemony. In this context, the United States (US) continues its strategy of containing China through trilateral cooperation with Japan and South Korea.[i] However, tariff policies implemented during the second Trump administration—such as the imposition of new high tariffs on Japan and South Korea—[ii] have caused shifts in the balance of power. As a result, economic rapprochement among Japan, South Korea, and China has accelerated.[iii]
This rapprochement presents a complex picture due to the historical tensions between Japan and South Korea, as well as both countries’ reliance on defense agreements with the United States. On August 23, 2025, the summit in Tokyo between Japanese Prime Minister Shigeru Ishiba and South Korean President Lee Jae-myung strengthened this rapprochement with the first joint press statement in 17 years.[iv] Additionally, South Korean Foreign Minister Cho Hyun’s visit to China on September 17, 2025, will provide an opportunity to meet with Chinese Foreign Minister Wang Yi to discuss Chinese President Xi Jinping’s participation in the Asia-Pacific Economic Cooperation (APEC) summit.[v] On the other hand, India’s IMEC project and the United States’ investments in Pacific Islands Forum (PIF) countries aim to create an alternative counterbalance to China. In this regard, the following questions arise: In light of historical tensions and existing security alliances, is economic rapprochement between Japan, South Korea, and China sustainable in the long term? How do initiatives such as IMEC and PIF reshape the balance of power in the Asia-Pacific?
Mearsheimer’s offensive realism theory argues that states pursue power maximization and that security competition is inevitable. China’s influence in the Asia-Pacific has been countered by alliances such as AUKUS, the Quadrilateral Security Dialogue (QUAD), and the US-Japan-South Korea cooperation institutionalized at the 2023 Camp David Summit. However, Trump’s tariff policies are testing the limits of Mearsheimer’s theory by demonstrating that economic factors can overshadow security-focused competition.
On August 23, 2025, the Japan-South Korea Summit held in Tokyo concluded with the first joint press statement in 17 years. Lee Jae-myung’s declaration that he would uphold the agreements made with Japan by previous conservative administrations (Park Geun-hye and Yoon Suk-yeol) alleviated Japan’s concerns about an “anti-Japan” government. This summit aimed to develop a joint strategy against Trump’s tariff policies and to strengthen economic cooperation. However, the deterioration of relations during the Shinzo Abe and Moon Jae-in period (2018–2020) demonstrates that historical tensions cannot be easily overcome.
South Korean Foreign Minister Cho Hyun’s visit to China in September aims to discuss Xi Jinping’s participation in the October 2025 APEC Summit. This visit reflects South Korea’s effort to strengthen economic ties with China, while potentially serving to balance China’s rapprochement with North Korea. Seoul is encouraging Beijing to play a constructive role in drawing Pyongyang into dialogue.
As part of alternative strategies, India’s IMEC project offers an economic and geopolitical alternative to China’s KYG, while the US’s support for India’s candidacy for permanent membership in the United Nations (UN) Security Council in 2025 and its increased transfer of defense technology have the potential to create a new balance against China. Similarly, US investments in the Pacific Islands aim to limit China’s influence in the region. However, it is debatable how effective these initiatives will be in counterbalancing Japan and South Korea’s economic rapprochement with China.
The economic rapprochement among Japan, South Korea, and China can be interpreted as a consequence of Trump’s tariff policies, with the August 23, 2025, Japan-South Korea Summit and the March 31, 2025, trilateral meetings reinforcing this process. However, this rapprochement remains “fragile” due to historical tensions between Japan and South Korea and both countries’ reliance on defense agreements with the United States. Although South Korean Foreign Minister Cho Hyun’s visit to China reflects efforts to advance economic cooperation, the likelihood of security collaboration with China remains low. Meanwhile, India’s IMEC project and U.S. investments in PIF countries present a multifaceted strategy to contain China. However, Trump’s unpredictable policies may draw U.S. allies in Asia closer to China, temporarily overshadowing Mearsheimer’s prediction of security competition by economic factors; nonetheless, it is unlikely that this competition will disappear entirely in the long term. This rapprochement between Japan and South Korea, driven by economic necessity, appears unsustainable due to historical and geopolitical dynamics. Initiatives such as IMEC and PIF may enhance US strategic flexibility, but China’s economic appeal remains a powerful magnet, particularly for actors like Japan and South Korea.
Mearsheimer’s offensive realism theory has proven correct in pitting China and the US against each other by predicting that the anarchic international system inevitably drives states into a competition for power and that peaceful rise is impossible. However, the theory’s margin of error is becoming apparent in today’s complex global dynamics. Initiatives such as the Belt and Road Initiative (BRI) are particularly indicative of China’s peaceful rise. Economic rapprochement triggered by Trump’s tariff policies, economic interdependence, and global institutions (such as APEC and BRICS) are softening security competition, calling into question Mearsheimer’s static power maximization model.
While offensive realism aptly captures states’ survival instincts and hegemonic drives, it underestimates the chains of interdependence and normative pressures created by globalization—such as the erosive effect of trade agreements on geopolitical alliances. This presents a critical limitation of the theory, making it increasingly unpredictable in shifting global balances (for example, when economic isolation draws allies closer to a rival). Ultimately, the balance of power in the Asia-Pacific is being reshaped less by realism’s stark vision and more by the gray zones of economic pragmatism and the chaotic nature of international relations, creating a hybrid reality that both confirms and exceeds Mearsheimer’s theory.
[i] “Can China Rise Peacefully?”, The National Interest, https://nationalinterest.org/feature/can-china-rise-peacefully-10204, (Accessed: 14.09.2025).
[ii] “Executive Order 14257”, Federal Register, https://public-inspection.federalregister.gov/2025-06063.pdf, (Accessed: 14.09.2025).
[iii] “China, Japan, South Korea will jointly respond to US tariffs, Chinese state media says”, Reuters, https://www.reuters.com/world/china-japan-south-korea-will-jointly-respond-us-tariffs-chinese-state-media-says-2025-03-31/, (Accessed: 14.09.2025).
[iv] “Japan-South Korea Relations: Summit Signals Change in Direction”, The Diplomat, https://thediplomat.com/2025/09/japan-south-korea-relations-summit-signals-change-in-direction/, (Accessed: 14.09.2025).
[v] “South Korea foreign minister to visit China this week, Yonhap reports”, The Standard, https://www.thestandard.com.hk/china-news/article/311496/South-Korea-foreign-minister-to-visit-China-this-week-Yonhap-reports, (Accessed: 14.09.2025).
