Why ‘Pacifist' Japan Has China Worried

Beijing has in recent months become increasingly vocal in its campaign against Japan’s push to strengthen its defense posture and position itself as a more active security partner in the Indo-Pacific.

‘Remilitarization’

Chinese military officials have characterized the security push as “remilitarization” in defiance of its pacifist postwar constitution, pointing to a series of defense initiatives, including deeper cooperation with other key United States allies and partners in the region.

At the root of the current chill in China-Japan ties was Japanese Prime Minister Sanae Takaichi’s November remark that a Chinese attack on-or blockade of-Taiwan could constitute a “survival-threatening situation,” a legal threshold that would permit the Japan Self-Defense Forces to use force alongside an ally, such as a hypothetical U.S. task force.

China demanded a retraction and responded with a range of retaliatory measures, from reductions in some Japan-bound flights by major Chinese airlines to curbs on rare-earth exports that Beijing says are intended to prevent strategically sensitive materials from reaching foreign defense industries.

Newsweek reached out to the Chinese and Japanese Foreign Ministries via email for comment.

Pacifist?

Japan’s postwar constitution prohibits maintaining traditional military forces designed for offensive warfare and renounces war as a sovereign right.

Former Prime Minister Shinzo Abe sought a larger security role for Japan amid China’s rapid military buildup, rising pressure on Taiwan and escalating tensions over disputed islands in the East China Sea.

Abe reinterpreted Article 9 to permit limited collective self-defense, established a National Security Council and eased long-standing restrictions on defense exports.

Buoyed by a historic supermajority in the House of Representatives, Takaichi has sought to build on her mentor’s legacy. In February, her government approved limited exports of lethal weapons to partner countries for the first time, albeit under strict end-use restrictions.

Tokyo also reached its goal of raising defense spending to 2 percent of GDP ahead of schedule and has pressed ahead with plans to reinforce remote islands along Japan’s southwestern frontier.

Japan’s Defense Ministry said Monday it had begun shipping a Type 12 surface-to-ship missile launcher to Minamitorishima, Japan’s easternmost island. Earlier this year, the ministry also confirmed plans to deploy Chu-SAM surface-to-air missile units on Yonaguni, just 70 miles from Taiwan, a move Beijing denounced as “extremely dangerous.”

Japanese Defense Minister Shinjiro Koizumi on May 31 said defense authorities play a “crucial role” in maintaining a “free and open Indo-Pacific”-the strategic concept first championed by Abe.

“Military buildups and actions without clear intentions will be the cause of distrust and miscalculation,” he stated, in a thinly veiled criticism of China.

Countries should pool their capabilities to build “effective deterrence and response capabilities” through joint training, intelligence sharing, technology cooperation and defense-industrial collaboration, he said during a forum at the Shangri-La Dialogue, the annual defense summit hosted by the International Institute for Strategic Studies in Singapore.

Philippine-Japan Alignment

Few relationships better illustrate Japan’s expanding security role than its deepening partnership with the Philippines. Both countries are treaty allies of the United States and face growing pressure from China’s expanding maritime presence in nearby waters.

Also at the event, Koizumi and his Philippine counterpart, Gilberto Teodoro Jr., agreed to accelerate discussions on the transfer of 2,000-ton Abukuma-class frigates Japan is set to retire. Manila hopes to eventually acquire five vessels, which Teodoro said could enter service “probably in a year or two.”

Japan has already supplied the Philippines with radar systems to strengthen maritime domain awareness. Philippine officials have also expressed interest in Japan’s Type 88 anti-ship missile, which, with a range of roughly 125 miles, could become one of the first lethal Japanese defense exports under Tokyo’s relaxed rules.

Manila is in the midst of a decade-long, roughly $35 billion military modernization effort aimed at improving surveillance, coastal defense and naval capabilities as it pushes back against China’s growing presence inside the Philippines’ exclusive economic zone.

Japan selected the Philippines as the first recipient of its Official Security Assistance program, which provides defense-related support to what Tokyo describes as like-minded partners.

Earlier this year, the Philippines became the third country-and the first in Asia-to conclude a Reciprocal Access Agreement with Japan, streamlining the deployment of troops for joint exercises and other military activities.

Another milestone came this year when Japanese forces joined the Balikatan exercises in the Philippines for the first time, marking the return of Japanese troops to the country for military drills since World War II.

Tokyo and Canberra Draw Closer

Japan has also been strengthening its defense ties with Australia.

Australia, like the Philippines, has moved to strengthen military interoperability with Japan through a reciprocal troop access agreement that streamlines the movement of personnel and equipment.

In December, Koizumi and Australian Deputy Prime Minister Richard Marles launched a framework to increase coordination on defense policy, intelligence sharing, joint activities and cooperation across the cyber, space and missile-defense domains.

Australia’s decision to acquire three and later co-develop eight of Japan’s Mogami-class frigates marked the largest defense-industrial partnership in Tokyo’s postwar history.

Japan’s Latent Nuclear Capability

China has also raised questions about Japan’s large stockpile of plutonium, arguing that it exceeds foreseeable civilian requirements and could provide the basis for a rapid nuclear breakout capability. The criticism intensified after a senior adviser to Takaichi suggested earlier this month that Japan should begin discussing the possibility of acquiring a nuclear deterrent in light of the expanding arsenals of China and North Korea.

Such a move would require abandoning Japan’s Three Non-Nuclear Principles: not possessing, producing or permitting the introduction of nuclear weapons.

Japan possesses the overwhelming majority of the plutonium held by non-nuclear-weapon states and remains unique among them in maintaining a complete civilian nuclear fuel cycle, including commercial reprocessing capabilities that allow plutonium to be extracted from spent reactor fuel.

While the stockpile is intended for civilian use in mixed-oxide fuel, the International Atomic Energy Agency generally considers about eight kilograms of separated plutonium sufficient for one nuclear weapon. Japan’s inventory is therefore theoretically large enough to produce thousands of warheads.

“In terms of a single weapon, on the order of six to 12 months is a fairly conservative estimate, given industrial capacity, facilities, expertise in nuclear science and, of course, the availability of physical materials,” Ankit Panda, a nuclear policy expert at the Carnegie Endowment for International Peace, told Newsweek.

However, Panda said Japan is unlikely to pursue nuclear weapons unless confidence in U.S. security guarantees fundamentally collapses.

“So what we’re really seeing is hedging-investing in nuclear latency, building a Plan B, so to speak,” he said.

A January poll conducted by Jiji Press found 62.6 percent of Japanese opposed Japan acquiring nuclear weapons, compared with 16.7 percent who supported the idea.

A Regional Connector

In his Shangri-La remarks, Koizumi hailed “efforts to support each country to choose for itself, to defend itself, and to contribute to regional stability.”

“Japan is hoping to be a reliable partner for that purpose. And Japan is hoping to serve as a connecting point that brings together the efforts of the region,” he said.

The wording suggests Tokyo increasingly sees itself in a leadership role, according to Robert Ward, Japan Chair and director of the International Institute for Strategic Studies’ geo-economics and strategy program.

Ward said Japan is seeking not only to strengthen ties with the Association of Southeast Asian Nations but also to position itself as a bridge between the region and the United States.

At the same time, he argued, Tokyo’s growing activism does not diminish the central role of the U.S.-Japan alliance.

“In a sense, Japan’s pushing on a bit of an open door with some countries that are also worried about China,” Ward said. “But that doesn’t change the primacy of the U.S. security alliance.”

Notably, Beijing’s “remilitarization” refrain appears to have gained little traction beyond China and North Korea.

A recent survey by the ISEAS–Yusof Ishak Institute found Japan was viewed as the most trusted major power in Southeast Asia, with 65.6 percent of respondents naming it their preferred partner.

2026 NEWSWEEK DIGITAL LLC.

This story was originally published June 9, 2026 at 3:00 PM.