As the new year unfolds, China finds itself grappling with strategic pressures fuelled by two US treaty allies at its doorstep – Japan and South Korea. In the first of a two-part series, Seong Hyeon Choi looks at how historically fraught China-Japan ties might fare as Tokyo bolsters its military posture with record budgets and advanced weaponry.
China and Japan have never fully resolved the decades-old grudges of their wartime history and territorial disputes, but it was near the end of 2025 – the 80th anniversary of the end of World War II in Asia – that military tensions seemed to stir in ways rarely seen for years.
The Donald Trump administration’s National Security Strategy, released in December, included a pledge to deter conflict in the first island chain with the focus on the Taiwan Strait.
The series of islands and archipelagos along the eastern edge of continental Asia, stretching from Japan through the Philippines, is part of a US containment strategy to restrict Chinese military access to the Pacific Ocean.
The security document stressed that the United States “must urge” allies such as Japan and South Korea to increase their share of the defence burden to “deter adversaries and protect the first island chain”.
Also in December, a Pentagon report warned that the Chinese military build-up was leaving the US “vulnerable”, adding to the pressure on Washington’s Indo-Pacific allies to boost defence spending and driving the region towards a tense crossroads between China and its neighbours.
Analysts say regional pressure is likely to intensify as China’s military activities persist and Japan bolsters its long-range counterstrike missiles as part of collective defence in the first island chain.
Tensions between Beijing and Tokyo have spiralled since Japanese Prime Minister Sanae Takaichi suggested in November that Japan could take military action in the event of an attack on Taiwan.
Her remarks prompted strong protests as well as economic and diplomatic retaliation from Beijing, which sees Taiwan as part of China to be reunited by force if necessary.
Most countries, including the US and its treaty ally Japan, do not recognise self-governed Taiwan as an independent state, but Washington is opposed to any forcible change to the status quo and is legally bound to supply Taipei with weapons for defence.
The row escalated militarily when Tokyo said that Chinese J-15 fighters in international airspace near Japan’s Okinawa islands had locked fire-control radar on Japanese F-15 jets – a dangerous step towards weapon targeting. Beijing in turn accused Tokyo of harassing its forces during normal military exercises and training.
Dennis Wilder, a professor at Georgetown University and a former CIA official, said a “certain amount of underlying tension” between China and Japan would persist as long as Takaichi remained in office.
“Both sides have reasons to tone down the spat, particularly because of the economic dimensions of the relationship,” he said. “But she is unlikely to take steps to reassure Beijing on the military front because Japan is committed to countering the growing Chinese threat.”
Collin Koh, a senior fellow at the Institute of Defence and Strategic Studies at the S. Rajaratnam School of International Studies in Singapore, also said tensions “look set to persist” but did not rule out de-escalation.
However, both sides would be most likely to “entrench their respective positions while seeking an off-ramp”, he said.
“We would have to see whether Takaichi gets to meet Trump in early 2026 before his planned summit with [Chinese President] Xi [Jinping], and there could be a turning point in this. But until then, we will expect Beijing to keep up with the rhetoric against Takaichi,” Koh said.
“Given the ramping up of tensions over the radar-lock incident, both governments are likely to be mindful of provoking an armed provocation. So they’ll keep tensions confined to rhetorical and military posturing.”
The China-Japan spat has paralleled rising military tensions near the Taiwan Strait and East China Sea, prompting Tokyo to abandon its decades-long disarmament policy.
In late November, the Japanese cabinet approved a supplementary budget proposal that included 1.1 trillion yen (US$7.1 billion) in additional defence spending, taking the total to 11 trillion yen – or more than 2 per cent of the country’s gross domestic product.
Tokyo has barred its defence spending from exceeding 1 per cent of GDP since the end of World War II.
The approval followed the defence ministry’s budget request in August for around US$60 billion in the next financial year, prioritising long-range missiles and naval procurement programmes seen as significant to deterring People’s Liberation Army advancement in the first island chain.
Japanese anti-ship missiles could potentially deny the PLA Navy’s advance across the first island chain and impede access to the eastern flank of Taiwan, deemed essential to any attack on the island.
Numerically, the PLA Navy has the largest fleet in the world, which it continues to modernise with the “goal of achieving sea superiority during a conflict over Taiwan”, according to the December Pentagon report.
The report noted that China maintained a “large reserve” of operationally ready ships that enabled it to “expand its persistent patrol presence and surge forces during crises and war”.
After the November inauguration of the Fujian, its third aircraft carrier, the PLA Navy was likely to increase its fleet of carriers to nine by 2035, it said.
These developments would enhance its blue water capabilities, potentially driving increased military activities across the first island chain.
Such a manoeuvre would require the Chinese naval fleet to penetrate the waters between Japan’s southwestern islands, which host US troops as well as future Japanese anti-ship missile bases.
Koh said that Japan’s record-breaking defence budgets would not result in any let-up in the PLA’s military activities.
“It doesn’t mean deterrence fails, but beyond the military build-up, much of what we see persisting so far has been peacetime military activities, including what most would call grey-zone actions,” he said, referring to non-military activities aimed at undermining adversaries’ defences without triggering a full-scale war.
“If deterrence holds, we assume also that Beijing will remain conscious of the US-Japan security alliance and be wary of accidentally provoking the invocation of the treaty obligations, given consistent signalling by Washington.”
Liselotte Odgaard, a senior fellow at the Hudson Institute in Washington, noted that the Japanese defence ministry flagged the increasing PLA build-up as a justification for the spending boost.
Japan’s military build-up was “real and accelerating” and coastal and fleet stand-off missiles would “raise the cost of Chinese naval advancement and strengthen deterrence”, especially when integrated with US and partner forces, she said.
She said there was “potential for accidental skirmishes” in hotspots such as the Diaoyu Islands, disputed East China Sea islands controlled as the Senkaku Islands in Japan, “if confrontations escalate further”.
“The current diplomatic crisis is likely to redefine Japan-China relations permanently because Japan’s willingness to participate in a military conflict if Taiwan faces a survival-threatening situation is a red line for China,” she said.
“Japan under Takaichi appears committed to maintaining a firmer stance aligned with the US, likely deepening military cooperation and bolstering deterrence.”
Tokyo plans to deploy Type 12 surface-to-ship missiles at Camp Kengun in Kumamoto prefecture, on the western coast of Kyushu Island. With a range of 1,000km (621 miles), mainland China and North Korea would be well within reach of the upgraded anti-ship missile, which recently completed a test launch in the US.
In September, Tokyo said its Kongo-class Aegis destroyer JS Chokai was heading to the US for a year-long deployment that would include modifications and training to operate Tomahawk cruise missiles, which have a range of around 1,600km, by September 2026.
Japan signed a contract for 400 of the long-range missiles in January 2024, with plans to make all eight of its Aegis destroyers Tomahawk-capable, as well as two Aegis system-equipped vessel destroyers currently under construction.
Retired US Navy officer John Bradford, a Japan Foundation fellow at the Yokosuka Council on Asia-Pacific Studies, said Japanese “counterstrike” forces were intended to “destroy Chinese weapons systems before those weapons can attack Japan”.
Tokyo also had some of the “world’s best naval systems”, such as its destroyers and submarines, which would be “critical” to containing a PLA Navy force in a combat situation, he added.
“Regardless of how the recent spat plays out, Japan is set to increase its defence capabilities. The capacity development areas to watch will be medium and long-range weapons, unmanned systems and – most important – munitions stockpiles.”
Stephen Nagy, from the International Christian University in Tokyo, said Japan’s focus on anti-ship missiles and extended-range strike capabilities “fundamentally alters” the strategic calculus by threatening China’s naval assets before they leave port.
“But the real deterrent effect depends on demonstrating the political will to use them,” said Nagy, a professor of politics and international studies.
“China will respond asymmetrically through cyber operations, supply chain weaponisation and intensified pressure on Japanese companies in China rather than matching capabilities directly, as they recognise Japan’s technological advantages in precision systems.”
Tokyo’s increased missile deployment has been opposed by Beijing, especially near the East China Sea. In November, Chinese foreign ministry spokeswoman Mao Ning said the deployment of Japanese missiles near Taiwan was a “deliberate move that breeds regional tensions and stokes military confrontation”.
Mao was responding to Japanese Defence Minister Shinjiro Koizumi’s remarks the same month, which outlined Tokyo’s plans to deploy medium-range surface-to-air missiles on Yonaguni Island, around 100km from Taiwan.
Wilder at Georgetown University said that while Japan’s weapons acquisitions were important, of greater significance was the greater coordination and integration of Japanese and US warfighting capabilities.
“The new wartime command established in Tokyo, and its US equivalent, will be a big step in the development of serious Japanese defence capabilities,” he said, adding that Tokyo appeared to be more dedicated to deterring Beijing’s pressure than previously.
Odgaard said that the security pressure on China would “intensify across multiple axes, not only in the Taiwan Strait”, but also in the East China Sea, South China Sea and Korean waters.
She said the combination of allied missile networks, undersea enhancements and US strategic signalling would force China to “allocate more resources to defence and deterrence, raising the risk of friction and miscalculation”.
“China is likely to respond with expanded naval deployments, such as dual-carrier operations and more submarines; hypersonic and anti-ship ballistic missile exercises to stress US and allied surface forces,” Odgaard said.
“But these moves will not change the fact that China faces more capable, networked adversaries in 2026 than previously.” -- SOUTH CHINA MORNING POST
