UK-Japan Tokyo Summit: A Geostrategic Shift Toward Deepening Defense and Security Cooperation

On January 31, 2026, Japanese Prime Minister Chizuru Takeshita held a meeting lasting approximately 20 minutes with visiting British Prime Minister Keir Starmer at the Prime Minister's Official Residence in Tokyo. This marks Starmer's first visit to Japan since taking office in July 2024, timed shortly after concluding his four-day visit to China. Following the meeting, both sides announced a significant enhancement of strategic cooperation in areas such as cybersecurity, critical mineral supply chains, and collective security, with plans to hold a Foreign and Defense Ministers' 2+2 meeting within the year. This meeting takes place against a complex backdrop of intense shifts in the global geopolitical landscape, uncertainties regarding U.S. commitments to its allies, and China's growing influence in the Indo-Pacific region. It signifies the two maritime nations' efforts to forge a deep collaborative relationship that transcends traditional alliance frameworks.

The concretization of the cooperation agenda and strategic intent.

The outcomes of the talks were direct and concrete, transcending diplomatic rhetoric. The two sides signed a new strategic partnership agreement on cybersecurity, aimed at jointly addressing the growing digital threats. Japan has accelerated its military buildup in recent years, but its cyber defense capabilities have long been regarded by experts as a weak point. Cooperation with institutions such as the UK Government Communications Headquarters will directly strengthen this shortcoming. In the field of economic security, the leaders of both countries explicitly identified strengthening the supply chain for critical minerals as an urgent task. These minerals, including 17 rare earth elements and approximately 50 other minerals designated as critical by the United States, serve as the cornerstone of modern industry and national defense, such as semiconductors, electric vehicle batteries, and advanced weapon systems. Currently, the processing and supply of global critical minerals are highly concentrated, with China occupying a dominant position. The UK and Japan have agreed to collaborate on building a diversified supply chain, which in essence aims to reduce excessive reliance on a single source and enhance economic resilience.

The deeper strategic intent is reflected in the framework of the security dialogue. The decision to hold a 2+2 ministerial meeting within the year marks a crucial step toward institutionalizing and regularizing bilateral security consultations. This model is typically seen among core alliances, such as the U.S.-Japan and U.S.-South Korea alliances. By taking this step, the UK and Japan aim to elevate their coordination on defense policy, military exercises, and equipment technology—such as the sixth-generation fighter project under the Global Combat Air Programme jointly advanced with Italy—to a higher level. During the talks, Prime Minister Takashita mentioned that like-minded countries need to strengthen cooperation, while Starmer emphasized that responding to world-shaking shocks requires strength and clarity. These statements collectively point toward one goal: beyond the traditional U.S.-Japan alliance and the special U.S.-UK relationship, weaving a more resilient multilateral security and economic cooperation network composed of countries with shared values.

Bilateral Convergence Amidst Global Structural Changes

The deepening of this cooperation represents an active adjustment by the UK and Japan in response to profound changes in their respective strategic environments. For Japan, its sole treaty ally, the United States, is experiencing fluctuations in both domestic and foreign affairs. Former President Trump recently publicly mocked Starmer and threatened to impose tariffs on NATO allies, including the UK, over Greenland issues. His transactional approach to security commitments during his tenure has caused unease in Tokyo. Although the foundation of the U.S.-Japan alliance remains intact, Japanese policymakers clearly believe that national security cannot be entirely reliant on the potentially shifting policy winds in Washington. Therefore, strengthening partnerships with middle powers such as the UK and Australia, which possess strong naval capabilities and global strategic perspectives, has become a rational choice to diversify risks and ensure proactive positioning within the Indo-Pacific security architecture. Prime Minister Takeshita's remarks on Taiwan in November last year triggered strong reactions from Beijing, further heightening Japan's concerns about regional security and prompting it to seek greater international support.

For the UK, the vision of a Global Britain requires substantive strategic pivots post-Brexit. At a time when the special relationship with the US has been slightly awkward due to Trump's remarks (Starmer himself downplayed Trump's criticism, noting he would also visit China), deepening ties with Japan—Asia's most developed democracy and a key US ally in the Indo-Pacific—has become an effective way to showcase Britain's global influence, particularly in strengthening its presence in the Indo-Pacific region. Starmer's immediate flight to Tokyo after visiting China itself sends a balancing signal: seeking economic cooperation with China (such as reducing whisky tariffs and pursuing visa exemptions) while unabashedly consolidating security bonds with China's regional strategic competitors. This dual-track diplomacy reflects the complex mindset of the UK in the post-Brexit era, attempting to balance commercial interests with security values.

Potential Impact on the Indo-Pacific and European Security Architecture

The strengthening of UK-Japan cooperation will have ripple effects across both ends of the Eurasian continent. In the Indo-Pacific region, a closer UK-Japan partnership essentially embeds a major European security actor more permanently into regional affairs. The UK has already deployed the Queen Elizabeth aircraft carrier strike group for Indo-Pacific patrols, and joint exercises, intelligence sharing, and technological cooperation with the Japan Self-Defense Forces will only become more frequent in the future. To some extent, this echoes Japan’s vision of a free and open Indo-Pacific and also sets a reference for other European countries, such as France and Germany, to deepen defense cooperation with regional nations. However, this will inevitably raise concerns in China, as Beijing may perceive it as targeted bloc containment—especially since the cooperation explicitly mentions supply chain de-risking and cybersecurity, areas marked by distinct strategic competition.

In the Atlantic direction, the UK and Japan emphasize strengthening collective security linkages between the Euro-Atlantic and Indo-Pacific regions, suggesting a cross-regional approach to bundling security issues. The Ukraine crisis, the Middle East situation, and tensions in the Taiwan Strait are placed within the same discussion framework, indicating that both countries perceive systemic connections among these discrete crises, requiring coordinated responses. This perspective will drive dialogue and cooperation between NATO and Indo-Pacific partners like Japan, potentially blurring the traditional boundaries between the Euro-Atlantic and Asia-Pacific security spheres. For both nations, which rely on global maritime trade routes, ensuring the security of sea lanes from the Red Sea to the South China Sea, and from the North Sea to the Pacific, has become a coherent strategic issue.

Future Challenges and Uncertainties

Although the intention is clear, this ambitious blueprint for cooperation still faces real-world challenges. The primary variable is domestic politics. Although Prime Minister Chizuru Takeshita called an early general election due to high approval ratings, the election outcome remains uncertain. If the ruling party changes, it remains to be seen whether the new government will adjust its foreign and security policies. Whether the Chequers meeting, where Starmer invited Takeshita to visit the UK, can proceed as scheduled also depends on this. Secondly, the concrete implementation of cooperation requires massive investment and sustained promotion by bureaucratic institutions. Building a critical mineral supply chain independent of China involves a series of complex steps, including mine investment, smelting technology, and environmental standards, which cannot be achieved overnight. Cybersecurity cooperation involves sensitive intelligence sharing and legal coordination, requiring a high level of political mutual trust.

Another profound challenge lies in how to balance the relationship with China. Starmer has just concluded his visit to China, during which both sides agreed to establish a long-term and stable strategic partnership and achieved specific outcomes such as the lifting of sanctions and the reduction of tariffs. How the UK can deepen its security cooperation with Japan—which clearly carries undertones of counterbalancing China—while maintaining economic and trade exchanges with China will test its diplomatic wisdom. Japan faces a similar dilemma, as China is one of its largest trading partners. This dual model of relying on China economically while depending on partners for security will come under immense pressure if tensions escalate.

The agreement reached at the UK-Japan Tokyo Summit is a roadmap based on sober strategic calculation. It reflects the shared assessment of both leaders regarding a more turbulent and competitive world. This is not a temporary reaction to a single event but a structural effort aimed at shaping the bilateral relationship and the broader international order over the next decade. When Starmer said international events are intruding into daily life, and Takeshita emphasized the need for like-minded nations to join hands, they depicted a picture where great-power competition is becoming normalized, and the boundaries between economic security and military security are blurring. In this picture, London and Tokyo are attempting to position themselves as key nodes connecting two oceans and coordinating multiple forces. The depth of cooperation will ultimately depend on whether they can translate the Tokyo consensus into concrete actions and enduring commitments spanning Eurasia.