Japan’s Perception and Response to the  Second Trump Administration​

Ki-Tae Lee

Senior Research Fellow, Sejong Institute​

Summary  

The perception and response of Japan to the launch of a second Trump administration must be analyzed within the framework of the U.S.-Japan alliance and the future development of the Indo-Pacific strategy. On January 20, 2025, President Donald Trump inaugurated, marking the beginning of his second term in office. During his first term, the U.S.-Japan alliance was strengthened based on personal rapport between Prime Minister Abe and President Trump. Abe’s “Free and Open Indo-Pacific (FOIP)” vision was embraced by the Trump administration, evolving into the foundation of the U.S. Indo-Pacific strategy.

Given Trump’s return to power and the anticipated shifts in the international order, it is important to examine how Japan perceives these changes and how it is responding in terms of foreign and security policy. During his presidential campaign, Trump suggested possible changes to U.S. foreign policy, including an early end to the Russia-Ukraine war, continued strategic competition with China, and a potential reopening of dialogue with North Korean leader Kim Jong-un. Since the outbreak of the Russia-Ukraine war, Japan has revised its National Security Strategy, aiming to acquire “counterstrike capabilities” and increase its defense budget to 2% of GDP. Under the Biden administration, Japan worked to enhance the U.S.-Japan alliance and developed a lattice-like security architecture by strengthening minilateral security cooperation networks such as the Quad (U.S.-Japan-Australia-India), South Korea-U.S.-Japan, U.S.-Japan-Philippines, and U.S.-Japan-Australia.

It is necessary to examine whether there is an element of “continuity” in Japan’s approach to U.S. policy by comparing its responses during the first and second Trump administrations. In terms of continuity, Japan’s foreign policy has traditionally followed a dual track of “omnidirectional diplomacy” (based on the 1957 principles of Japanese foreign policy: UN-centered approach, alliance with the Western bloc, and Asian diplomacy) and a “situationally adaptive diplomacy.” During Trump’s first term, Japan responded to Trump’s de-emphasis on bilateral alliances by pursuing improved relations with China and strengthening security networks with India, Australia, and Europe within the framework of its traditional “omnidirectional diplomacy.” Moreover, in response to the Trump administration’s North Korea policy, Japan demonstrated a typical example of “situationally adaptive diplomacy.” Prior to the North Korea-U.S. summit, Japan emphasized a sanctions-based approach, but afterward, then Prime Minister Abe explored new initiatives, including the possibility of an “unconditional meeting with Kim Jong-un.”

In Trump’s second term, Japan’s foreign policy will likely hinge on whether trilateral cooperation with the U.S. and South Korea regarding North Korea’s denuclearization and issues on the Korean Peninsula can be sustained, as well as whether Japan will pursue its own independent diplomatic initiatives toward North Korea. Japan’s perception of and response to the Trump administration can offer important policy implications for South Korea’s approach to Trump’s second term and future South Korea-Japan cooperation. In particular, it may inform policy options regarding the sustainability of trilateral cooperation among South Korea, the U.S., and Japan in response to potential future North Korea-U.S. dialogue on denuclearization, as well as the continued enhancement of Japan–South Korea security cooperation. Furthermore, it can contribute to proposals for strengthening trilateral security cooperation under the global lattice-like alliance framework. In relation to ongoing tensions between South Korea and Japan—including historical disputes—Japan’s response also raises the issue of how the two countries might manage bilateral conflicts, either with the involvement of the U.S. or under a more non-interventionist U.S. approach.

The postwar history of U.S.-Japan relations has been characterized largely by the dynamic of American “demands” and Japan’s “resistance and accommodation” regarding the division of roles within the alliance. During the Cold War, the U.S. consistently called on Japan to expand its regional military role, including rearmament. However, Japan adopted the so-called Yoshida Doctrine, entrusting its security to the U.S. while focusing on economic reconstruction. Japan’s pacifist constitution and prevailing public sentiment also limited its willingness to take on a greater security role in East Asia.

In the post–Cold War period, Japan began advocating for greater international contributions and pursued a path toward becoming a “normal country.” Following the 1990 Gulf War, Japan’s push for constitutional revision and the strengthening of the U.S.-Japan alliance gained momentum. This drive was especially intensified after the launch of Abe’s second cabinet in December 2012. Abe actively promoted both the revision of the pacifist constitution and a more robust U.S.-Japan alliance as part of Japan’s normalization strategy. Although the constitution was not formally amended, the cabinet decision on July 1, 2014, to reinterpret the constitution and allow for the exercise of collective self-defense had the practical effect of constitutional revision. The enactment of security legislation in 2015 and the revision of the U.S.-Japan Defense Guidelines marked a significant step toward Japan’s full realization of its “normal country” agenda, expanding its international contributions based on a strengthened U.S.-Japan alliance.

Since the 2010s, the rise of China has been a key factor driving Japan to strengthen the U.S.-Japan alliance. Concerned about China’s growing military capabilities, Japan outlined a strategy in its 2013 National Security Strategy that emphasized the reinforcement of the U.S.-Japan alliance, the enhancement of its own defense capabilities, and the expansion of international security networks. Although Abe’s revisionist stance on historical issues raised concerns about the alliance, the mutual visits between President Obama and Abe in 2016—Obama’s visit to Hiroshima and Abe’s visit to Pearl Harbor—helped resolve the “U.S.-Japan dilemma” concerning history and security. As a result, historical issues that had previously hindered the strengthening of the security alliance were effectively shelved, allowing the two countries to further solidify their alliance in response to China’s military rise.

Regarding Trump’s security commitments to Japan, the Abe administration responded proactively and cooperatively. During the 2016 presidential campaign, Trump expressed dissatisfaction with what he viewed as the unfairness of the U.S.-Japan Security Treaty and called for Japan to shoulder a greater share of the costs for stationing U.S. troops, making unpredictable statements that unsettled Japan. He even stated that “if Japan is attacked, the U.S. would end up in World War III,” harshly criticizing what he saw as Japan’s free-riding on U.S. security. However, during Trump’s first term, these issues were mitigated by Abe’s large-scale purchases of high-priced American weapon systems, including the F-35 and Aegis Ashore. These purchases helped Abe curry favor with Trump and ease tensions between the two countries.

During Trump’s first term, the core of the Abe administration’s foreign policy was to keep the U.S. engaged in East Asia by strengthening the U.S.-Japan alliance. Japan’s foreign policy has fundamentally been rooted in “omnidirectional diplomacy” and “situationally adaptive diplomacy,” and Abe’s second administration continued this tradition. Since the launch of Abe’s second term in 2012, Japan worked to reinforce the U.S.-Japan alliance in response to China’s military build-up and the threat posed by North Korea’s nuclear and missile programs. The 2013 National Security Strategy laid out more concrete foreign and security policy objectives, including bolstering the U.S.-Japan alliance, enhancing Japan’s self-defense capabilities, and expanding international security networks.

In response to Trump’s unconventional approach to alliance management, the Abe administration doubled down on Japan’s traditional diplomatic principles of omnidirectional and adaptive diplomacy. As trade friction with the U.S. escalated, Japan sought closer ties with China and India, while also deepening cooperation with European nations. However, its efforts to build economic cooperation with Russia faced challenges due to President Putin’s hardline stance, and Japan’s diplomatic outreach to North Korea stalled because of the unresolved issue of Japanese abductees. The announcement of the Free and Open Indo-Pacific (FOIP) initiative in Nairobi, Kenya, in 2016 symbolized Japan’s commitment to strengthening the U.S.-Japan alliance in the face of China’s rise, while also reflecting efforts to expand global networks in anticipation of reduced U.S. engagement. Japan’s FOIP vision embodied the Abe administration’s fundamental belief that the Indo-Pacific region must be shaped in a way that is resilient and independent of the strategic competition between the U.S. and China.

At the outset of the Trump administration’s first term, Japan employed its characteristic “omnidirectional diplomacy” even in its approach to the U.S. During the presidential election, Japan’s Ministry of Foreign Affairs had anticipated Hillary Clinton’s victory. However, it simultaneously maintained contact with members of the Trump camp as a contingency. As a result, following Trump’s unexpected victory, Abe became the first foreign leader to visit Trump Tower. Thanks to their personal rapport, Trump frequently consulted Abe on matters concerning North Korea and China, allowing for close U.S.-Japan cooperation in East Asian diplomacy.

Amid growing speculation over Trump’s potential re-election, the term “Moshi-Tora”—short for “what if Trump is elected (again)”—emerged in Japan. Trump’s return to the political scene stirred unease among the Japanese public, as there were concerns that America’s “America First” stance might harm Japanese interests. Japan expressed concern that Trump’s election could introduce further unpredictability into the international order and U.S. policy toward Japan.

Nonetheless, there were also expectations within Japan that the U.S.-Japan alliance, as well as Trump’s pro-Japan inclinations, would continue under a second Trump administration. It was hoped that the U.S., recognizing Japan’s strategic importance, would refrain from making reckless demands. The personal bond between Abe and Trump contributed to Trump’s continued sense of affinity toward Japan, with Trump referring to Japan as a “great country” and expressing his respect for the Japanese people. There was also an expectation that Trump would continue to promote a stronger U.S.-Japan alliance.

Japan expressed concern over the influence of a “neo-Monroeism” in Trump’s diplomacy toward East Asia. Unlike the original 19th-century Monroe Doctrine, this modern version is characterized by the U.S. possessing overwhelming military capabilities to expand its national interest, while refraining from active external military interventions. Given the security threat posed by China, Japan sees continued U.S. engagement in East Asia as essential. In response, Japan has sought to enhance its own defense capabilities and proactively engage in burden-sharing with the U.S.

Given Trump’s tendency to make selective foreign policy engagements based on his own interpretation of American national interest, Japan has made efforts to either supplement or even substitute for the U.S. in safeguarding international liberalism. Japan has assessed that if Trump were to bring an early end to the Russia-Ukraine war, the reallocation of U.S. resources toward countering China could have a positive impact on Japan’s national security. Furthermore, Japan views the consequences of the Russia-Ukraine war and the conflict in the Middle East as significant factors affecting the security order of East Asia.

Trump’s political return is also closely linked to the North Korea issue. Japan has been considering its response in light of developments in U.S.-China relations and North Korean behavior. With the launch of a second Trump administration and a shifting U.S.-China relationship, Japan sees the need to recalibrate the international order in East Asia, particularly in relation to a potential Taiwan contingency.

During the 2024 U.S. presidential election, the Kishida administration actively sought to leverage its ties with former President Trump. Taro Aso, Vice President of Japan’s Liberal Democratic Party (LDP), visited Trump and emphasized his personal friendship with the former Prime Minister Shinzo Abe. In his meeting with Aso, Trump expressed a favorable view of Japan’s efforts to increase its defense spending. Through parliamentary diplomacy, the Japanese government aimed to strengthen ties with Trump. During his 2024 visit to the U.S., Kishida emphasized the importance of reinforcing the U.S.-Japan alliance and deepening cooperation in defense, striving to ensure the continuity of U.S. engagement in East Asia.

In his address to the U.S. Congress, Kishida highlighted the significance of the U.S.-Japan alliance and underscored the need for bipartisan cooperation. His core message was that the alliance serves U.S. national interests—a point he aimed to deliver to both Democrats and Republicans. Regardless of the outcome of the U.S. election, Japan maintained a strategic approach to managing its relations with both Trump and Biden, emphasizing the importance of strengthening the alliance. During the election period, Trump called on NATO member states to significantly increase their defense spending, a position that could also affect Japan. Trump demanded that NATO allies raise their defense budgets to 5% of GDP, sparking speculation that Japan might be expected to do the same. While Japan acknowledges the need to increase its defense spending, there is reluctance regarding Trump’s proposed level. Japan may set its target at 3% of GDP, which would require an estimated budget of 18 trillion yen.

In February 2025, during a U.S.-Japan summit, Ishiba preemptively pledged to Trump that Japan would double its defense spending by 2027. Ishiba emphasized that this decision would be made independently by Japan. A key challenge for Japan remains responding to U.S. pressure under a second Trump administration regarding the purchase of American-made weapons—an issue that will significantly impact Japan’s national security policy. The Ishiba administration has been preparing a wide range of policy proposals in anticipation of a second Trump term and is exploring a new security policy within the LDP. Ishiba is expected to pursue a strategy that strengthens Japan’s autonomous defense capabilities and seeks to recalibrate the U.S.-Japan alliance toward a more equal partnership.

Japan will continue to uphold its North Korea policy of demanding complete denuclearization, including the total elimination of nuclear weapons and ballistic missiles. On January 15, 2025, Japan reaffirmed that it could never recognize North Korea as a "nuclear power," in response to remarks made by Pete Hegseth, nominee for U.S. Secretary of Defense, who had described North Korea in such terms. On February 7, 2025, during the U.S.-Japan summit, Ishiba and Trump agreed to cooperate toward the “complete denuclearization” of North Korea. Japan remains committed to addressing the North Korean nuclear and missile threat through trilateral U.S.-Japan-South Korea security cooperation. The Ishiba administration will also strive to ensure that North Korea-U.S. dialogue presents an opportunity to re-raise the issue of Japanese nationals abducted by North Korea.

Japan is concerned that issues directly related to its security might be excluded from North Korea-U.S. negotiations. Under the Abe administration, Japan had previously worried that its interests were not adequately reflected in North Korea-U.S. dialogue, particularly regarding the threat of intermediate-range ballistic missiles (IRBMs) capable of striking the Japanese mainland. While Trump had focused on intercontinental ballistic missiles (ICBMs) that pose a direct threat to the U.S., Japan was uneasy about the relative neglect of regional threats.

The Trump administration is unlikely to alter its cooperative stance on the abduction issue. At the request of Abe, Trump consistently raised the issue of abducted Japanese citizens during summit talks with North Korean leader Kim Jong Un. A recent national security policy report by the America First Policy Institute (AFPI) stated that the Trump administration places the U.S.-Japan alliance as a top global priority and considers it the cornerstone of its Asia strategy. The report also affirmed the Trump administration’s commitment to North Korea’s denuclearization, deterring Chinese aggression in the South China Sea, and resolving the abductions of Japanese citizens. As such, U.S. cooperation on the abduction issue is expected to remain unchanged.

The Ishiba administration will continue the efforts of previous administrations to resolve the abduction issue. Since 2019, Japan has been seeking a summit meeting with North Korea. Although Ishiba had favored a gradual approach—such as establishing liaison offices in Tokyo and Pyongyang—during the LDP leadership race, after becoming Prime Minister, he expressed his willingness to pursue a top-level summit in line with previous prime ministers. Japan is also expected to stress international solidarity and urge the U.S. to maintain its attention on the abduction issue.

Trump’s political resurgence has provided China with further incentive to improve relations with Japan. In January 2017, the Trump administration criticized the U.S. trade deficit with China, raising tariffs on Chinese products and banning imports and sales of goods from Chinese telecommunications companies like Huawei. As U.S.-China trade friction intensified, China grew more motivated to improve relations with Japan. During the 2024 campaign, Trump advocated imposing a 60% tariff on Chinese imports and was expected to seek cooperation from allies, including Japan, in restricting high-tech exports to China, particularly semiconductors.

In November 2024, China implemented a visa exemption policy for short-term stays for Japanese nationals, aiming to attract Japanese tourists and investment. This was seen as part of China's efforts to break free from diplomatic isolation by approaching the Japanese government. The Ishiba administration places great importance on diplomacy in Asia and is actively working to improve relations with China. However, Japan continues to press China to resume imports of Japanese seafood and beef, to release detained Japanese nationals early, and to ensure the safety of Japanese citizens within China.

While managing potential conflict factors in the future of China-Japan relations, Japan seeks to pursue mutual benefits through cooperation. For instance, the China Coast Guard operated vessels equipped with deck-mounted guns for over 50 consecutive days outside the territorial waters near the Senkaku Islands. To avoid accidental clashes, Japan emphasizes communication and defense exchanges with the People’s Liberation Army. Moreover, due to concerns that military cooperation between North Korea and Russia could destabilize the situation on the Korean Peninsula, Japan seeks mutual benefits through enhanced cooperation with China.

During his first term, President Trump did not attend ASEAN-related summits, indicating a lack of interest in Southeast Asia. As a result, countries like Malaysia and Indonesia grew closer to China and Russia, and Trump’s policies may have further accelerated this shift. In contrast, Japan has maintained traditional friendly ties with Southeast Asian nations and is now reinforcing security cooperation to counter China’s expanding military influence. Ishiba chose Indonesia and Malaysia for his first overseas visits in 2025, signaling Japan’s strategic prioritization of Southeast Asia. Japan aims to play a supplementary or even coordinating role in place of the U.S. by working with Southeast Asian countries. Japan is moving forward with efforts to maintain and strengthen a free and open international order, including reforms of the United Nations Security Council.

Given the perception that Trump’s “America First” policy and pragmatic approach will remain the dominant trend in U.S. foreign policy, South Korea must develop a corresponding strategy toward the U.S. Washington is likely to continue demanding greater roles from South Korea in Northeast Asia, such as increased defense cost-sharing and involvement in Taiwan-related issues. Therefore, discussions in South Korea should move beyond focusing solely on the presence of U.S. troops or the rise in defense cost contributions. Instead, emphasizing the strategic importance of the ROK-U.S. alliance to Trump will help maintain stability on the Korean Peninsula and present South Korea as a valuable negotiating partner. For example, Japan proposed increasing energy imports from the U.S., including LNG, during the U.S.-Japan summit in February 2025. Although concerns remain about the continuity of ROK-U.S.-Japan security cooperation during Trump’s second term, expanding discussions to include emerging security fields such as artificial intelligence, space, and cybersecurity could make the administration view trilateral cooperation more favorably.

Furthermore, South Korea must have a clear understanding of both the ROK-U.S. alliance and the U.S.-Japan alliance. Japan has already achieved a near-equal alliance with the U.S. South Korea must recognize Japan’s importance in the U.S. Indo-Pacific strategy and understand that, while the ROK-U.S. alliance remains a bilateral arrangement largely focused on the Korean Peninsula, it features greater military integration and coordination than the U.S.-Japan alliance. Based on this, South Korea can emphasize the ROK-U.S. alliance’s role in countering China as part of a broader Indo-Pacific strategy. South Korea should also seek to strengthen the trilateral framework with the U.S. and Japan for North Korea’s denuclearization within a global alliance network structured around the U.S.-Japan alliance.

South Korea should actively argue that the ROK-U.S. and U.S.-Japan alliances provide effective means for countering China. China, after Trump’s election, has aimed to improve ties with South Korea to distance it from the U.S. alliance framework. Therefore, South Korea must clearly affirm its commitment to the ROK-U.S. and trilateral security cooperation. While it need not adopt a confrontational stance against China, it should emphasize that robust U.S.-South Korea and trilateral cooperation will be instrumental in addressing China-related issues over the long term. If the U.S.-Japan alliance has solidified into a global strategic alliance, the ROK-U.S. alliance should be promoted as a deeply integrated bilateral alliance with a long-standing history and superior operational capabilities.

South Korea should also pursue “omnidirectional diplomacy” centered around the ROK-U.S. alliance. Japanese diplomacy is characterized by its ability to maintain balance and strategic flexibility even when one side appears to prevail. Likewise, South Korea should adopt a priority-based cooperative diplomatic approach while maintaining the ROK-U.S. alliance as its core. It is important for South Korea to reassure China that it will not pursue exclusionary foreign policies like Japan’s omnidirectional diplomacy, and that the ROK-U.S. alliance remains its most vital value-based partnership.

It is essential to continuously advocate for the strengthening of the ROK-U.S. alliance under the Trump administration. While there are concerns that Trump may neglect bilateral alliances, it must be emphasized that reinforcing the ROK-U.S. alliance ultimately serves U.S. interests. During the U.S. presidential campaign, Japan clearly articulated its role-sharing responsibilities to both the Democratic and Republican parties within the framework of strengthening the U.S.-Japan alliance. South Korea must also recognize that instability in the ROK-U.S. alliance caused by political changes in South Korea could lead to broader instability in trilateral security cooperation and even the U.S.-Japan alliance, a point of concern for Japan.

As we enter 2025, it is important to reassess the current state of Korea-Japan relations in order to usher in a new era—Korea-Japan Relations 3.0. Since the normalization of diplomatic ties in 1965, the bilateral relationship has gone through stages: 1.0, followed by 2.0 marked by the Kim Dae-jung–Obuchi Joint Declaration in 1998. Now, a new era of 3.0 must be envisioned. While the relationship has become more equal and there is shared recognition of the need for security cooperation in response to international circumstances and regional threats, lingering issues—such as historical disputes and the territorial conflict over Dokdo—remain sources of tension.

It is necessary to maintain and strengthen existing Korea-Japan cooperation regarding North Korea’s complete denuclearization and missile threats. Both countries emphasize nuclear nonproliferation and adherence to the NPT regime, and they should reinforce cooperation in areas such as real-time information sharing, missile interception capabilities, and anti-submarine warfare. Moreover, South Korea must acknowledge that Japan may actively engage in North Korea policy at any time. Should inter-Korean relations continue to deteriorate, Japan may take on a mediating role in U.S.-North Korea dialogue or even initiate direct talks with North Korea after a breakthrough in U.S.-North Korea negotiations. Thus, maintaining the Korea-Japan relationship and keeping communication channels with Japan open is critical to enhancing trilateral cooperation.

Opportunities arising from Trump's return to office must be identified and leveraged in the context of Korea-Japan relations. South Korea should explore the possibility of nuclear policy cooperation with Japan, including Korea’s latent nuclear capabilities and Japan’s potential revision of its Three Non-Nuclear Principles. In response to Trump’s independent and unconventional foreign policy, Korea and Japan should align their strategies and seek coordinated responses. As middle powers, they must proactively engage in joint policy efforts to counterbalance the great-power competition between the U.S. and China.

Korea and Japan should examine areas for cooperation to strengthen nonproliferation efforts and trilateral security coordination with the U.S. For example, Ishiba has considered strengthening the U.S.-Japan alliance with China in mind, through initiatives such as an “Asian NATO” and nuclear-sharing discussions. On the Korean side, active participation in ROK-U.S.-Japan security cooperation aimed at countering North Korea is necessary. Historical issues between Korea and Japan should be addressed through conflict management. The U.S. has largely refrained from direct involvement in historical disputes between Korea and Japan, and this is likely to continue during Trump’s second term. Korea must work to sustain a cooperative mood with Japan and establish a consensus framework for managing historical disputes to prevent future tensions.

It is also essential to analyze the future prospects of trilateral cooperation between South Korea, Japan, and the U.S., particularly in light of the possibility of regime changes in Korea or Japan in 2025. Should a South Korean administration emerge that prioritizes a peace regime on the Korean Peninsula, or should Japan experience a change of government to the Constitutional Democratic Party, Trump may pursue a new format for trilateral security cooperation.

Lastly, during the Trump era, Korea and Japan must proactively seek a sustainable form of global-level cooperation—namely, “externalized security cooperation.” The two nations should pursue active engagement in minilateral and multilateral frameworks in non-traditional security domains, and they must jointly foster a shared understanding of cooperative security and role-sharing within the Indo-Pacific strategy. This approach should focus on partnership and complementarity, rather than competition, between Korea and Japan.