How Tokyo is widening regional defence ties to complicate Beijing’s Taiwan calculus
Tokyo is strengthening partnerships across the Indo-Pacific and beyond, possibly bolstering its ability to withstand a prolonged armed conflict
The push was on display in Australia last month, where Tokyo and Canberra moved to deepen cooperation, ranging from defence planning and advanced weapons development to the construction and sustainment of Japanese-designed warships.
But the deepening relationship with Australia is only part of a much broader shift.
With Taiwan increasingly shaping its defence planning, Japan is connecting regional military ties with defence-industrial and technological partnerships across North America and Europe.
The United States is Japan’s only treaty ally and security cornerstone, and Tokyo is looking to other countries to complement that relationship: from operational and logistical cooperation with Australia and the Philippines to weapons production, intelligence and more secure supply chains farther afield.
For Beijing, that could mean having to calculate not only Japan’s own military strength in a Taiwan conflict but also the wider network of countries that could help keep its forces supplied, its economy resilient and its defence industry running.
Beijing sees Taiwan as part of China to be reunited by force if necessary. Most countries, including the US and Japan, do not recognise Taiwan as an independent state, but Washington is opposed to any attempt to take the self-ruled island by force and is committed to supplying it with weapons.
“A wider network of partners could give Japan more options and make it harder for China to pressure Japan into accepting an early settlement,” Matsuoka said.
Christopher Hughes, a professor of international politics and Japanese studies at Warwick University, described Tokyo’s approach as a three-layered strategy: strengthening Japan’s own capabilities, integrating more deeply with the United States and building complementary ties with like-minded American allies and partners.
The first two remain at the core, Hughes said, meaning the blossoming relationships with regional partners and Nato member states are not intended to replace the US alliance.
Celine Pajon, head of Japan research at the French Institute of International Relations, echoed that analysis.
“Japan is not trying to replace the US alliance,” Pajon said. “It is trying to make itself less dependent on any single partner.”
For decades, the region’s US-led security architecture followed a “hub-and-spokes” model, with Washington at the centre of separate alliances with Japan, Australia and the Philippines.
Tokyo is now connecting those spokes through bilateral and minilateral arrangements while building ties beyond the traditional US alliance system.
Koizumi said this went beyond military access and exercises.
Asking what would happen if “necessary items run short and logistics are cut off” during a crisis, he called for partners to cooperate more closely on defence production, maintenance and sustainment.
That thinking is reflected in work on the coming revision of Japan’s three main security documents.
Defence ministry planning material calls for a “multilayered web of cooperation” spanning bilateral and minilateral frameworks, including the US alliance, Japan-US-Australia-Philippines cooperation and the Global Combat Air Programme.
Such convergence is particularly advanced in Japan’s relationship with Australia, where cooperation increasingly spans operations, defence planning, advanced technology, production and sustainment.
Under a defence coordination framework established in December, the countries have deepened cooperation across operations, intelligence, technology and industry.
On August 18, they agreed to let Japan use Australian ranges to test next-generation long-range precision-strike and autonomous systems, including those linked to its hypersonic missile programme.
The talks also highlighted successful field trials under Boobook, the countries’ first jointly funded defence research project, involving laser technology.
Meanwhile, Australia’s decision to acquire Japan’s upgraded Mogami-class frigate is creating plans to build and sustain the warships locally.
The tempo of cooperation has also accelerated sharply. Australian Defence Minister Richard Marles said he and Koizumi had met seven times over the past 12 months, while bilateral exercises were increasing “at a really significant rate”.
The relationship is also becoming a platform for wider regional partnerships. Japan, Australia and New Zealand launched trilateral defence-ministerial talks in May, while Japan, Australia and Indonesia held their first trilateral defence ministers’ meeting on August 26, agreeing to advance three-way cooperation across the Indo-Pacific.
In addition, Tokyo and New Delhi are expanding defence-industrial cooperation, adding another dimension to their deepening security relationship.
But it is in the Philippines, which is also embroiled in a territorial dispute with Beijing, where Tokyo’s push intersects most directly with the geography of a potential Taiwan conflict.
The Philippines’ security calculations have become entwined with Taiwan, with Manila quietly expanding unofficial security contacts with Taipei.
The country’s geography, US alliance and economic interests could make remaining outside a major US-China conflict difficult.
At the same time, Japan, the Philippines and the US have been deploying missile systems close to Taiwan along the first island chain, creating what some analysts describe as a tacit “division of labour” that could constrain the PLA in a conflict over the island.
Those capabilities are being accompanied by agreements aimed at deepening operational and logistical ties. A Japan-Philippines Acquisition and Cross-Servicing Agreement that entered into force in August enables reciprocal logistical support during joint operations and exercises.
It builds on a reciprocal access agreement that makes it easier for Japanese forces to train in the Philippines and conduct rotational deployments, alongside expanding defence equipment and sustainment cooperation.
Beijing views the trend differently.
For Beijing, the significance goes beyond more Japanese forces exercising overseas. Access, logistics and complementary capabilities could help dispersed forces operate across the first island chain, forcing mainland China to account for threats from several directions during a Taiwan contingency.
Sebastian Maslow, an associate professor at the University of Tokyo, said the emerging minilateral frameworks were intended to help deter Beijing while expanding Japan’s regional security role, amid growing concern about Washington becoming distracted by crises elsewhere.
According to Maslow, the network has three broad objectives: to offset the US’ eroding security role, deter China and expand Japan’s security footprint in the region.
But broadening operational ties across the Indo-Pacific is only one dimension of Japan’s internationalisation. Tokyo is also seeking industrial and technological depth through Europe, Canada and other partners that could help it sustain a prolonged crisis.
Nato has become one avenue for that expansion, with Japan deepening cooperation with the alliance on cyber defence, hybrid threats, technology and defence industry while strengthening bilateral relationships with individual member states.
“GCAP is about much more than building a fighter,” said Pajon, referring to the programme. “It is Japan learning to build defence capabilities internationally.”
But the potential wartime relevance of industrial cooperation extends beyond sophisticated platforms.
Hughes said these links could help Japan maintain a technological edge over China in some areas while reducing overdependence on the US, which has sometimes been less willing to export or license particular technologies.
European partners could also work with Japan on less “exquisite” but militarily useful systems, he said, including massed deployments of drones – equipment they might be able to supply during a regional contingency.
That trend is already visible in rising foreign interest in developing and producing drones and other defence technologies with Japanese industry.
Japan’s liberalisation of defence exports reinforces the process.
Tokyo has increasingly treated equipment transfers, joint development and industrial cooperation as instruments of security policy, particularly in Southeast Asia, where they can create long-term relationships involving training, maintenance, parts and upgrades.
Japan’s Official Security Assistance programme extends that approach by helping strengthen the capabilities of strategically located partners whose territory, waters or surveillance capacity could shape the wider regional environment during a Taiwan contingency. Recipients have included the Philippines, Indonesia and Malaysia.
Economic security is another component. Tokyo is seeking to reduce vulnerabilities including foreign weapons supplies that could be stretched by competing conflicts and dependence on China for critical materials and components.
Maslow said this reflected a broader conception of national security in Tokyo, with supply-chain resilience, trade and investment increasingly forming part of Japan’s strategic competition with China.
Pajon said that ultimately Japan’s expanding partner network was making China’s strategic environment “more complex and less predictable”, while Maslow similarly argued that Tokyo’s efforts had “complicated China’s security planning”.
In a Taiwan contingency, this means Beijing would have to factor in not only Japan’s own military capabilities but also Tokyo’s access to outside sources of technology, production, intelligence, economic support and political backing as a conflict continued.
Matsuoka described the broader objective as an attempt to build “strategic endurance”, giving Japan greater capacity to withstand the political, economic and military pressures accompanying a prolonged confrontation.
However, there are significant limits to what this network could deliver if deterrence failed.
Hughes said Japanese policymakers were “relatively clear-eyed” about European capabilities, adding that their defence commitments to the Indo-Pacific remained “quite limited and not to be relied on in a potential conflict over Taiwan”.
European submarines or aircraft carriers that sometimes sail to the region might play some role, he said, but more realistic contributions could include economic pressure or European navies assuming greater responsibility in the Indian Ocean, freeing US forces to concentrate on Japan or Taiwan.
Pajon likewise said Europe’s strongest contributions would probably come through diplomacy, sanctions, cyber and information operations, intelligence, capacity-building and selected military deployments rather than large-scale combat operations.
“The real value therefore lies in deterrence through a broader network of capable partners, not in assuming that Europe would provide large-scale military support if deterrence failed,” Pajon said.
Tokyo thus does not need every partner to fight the PLA for its growing network to have strategic value.
Sharing intelligence, producing components, repairing equipment, protecting shipping routes, imposing economic costs or assuming security responsibilities elsewhere could all help Japan sustain a Taiwan contingency.
But that distinction may carry little weight in Beijing, which already regards Tokyo’s expanding security relationships as a form of bloc-building.
China’s foreign ministry said in April that Japan had been “interacting frequently with Nato” in an effort to bring the “non-regional military organisation” into the Asia-Pacific, accusing Tokyo of “provoking confrontation”.
And for most of this year, Chinese state media and spokesmen have lashed out frequently at Japan’s defence push, comparing it with the country’s pre-World War II military build-up.
The perception gap between Tokyo and Beijing risks intensifying an already deepening security dilemma.
“The same network that makes Japan harder to isolate could also deepen the regional arms race,” Matsuoka said.
“From Japan’s perspective, these measures are largely defensive and intended to strengthen deterrence. From China’s perspective, they may look like Japan is becoming part of a wider military coalition.”