A Trial Balloon on Deterrence

A senior Japanese government official advising Prime Minister Sanae Takaichi on security policy publicly questioned Japan’s non-nuclear stance on December 18, 2025, arguing that Japan “should possess nuclear weapons” in light of a deteriorating regional security environment. 

The remarks, delivered to reporters and framed as a personal opinion, underscored growing unease within Japan’s security establishment over reliance on extended deterrence and the pace of military change in East Asia.  

The official pointed to nuclear threats from three directions: China’s expanding arsenal, Russia’s nuclear posture, and North Korea’s continued missile and warhead development. 

They emphasized strategic self-reliance, stating that “in the end, we can only rely on ourselves.” 

At the same time, the official stressed there were no active discussions inside the government, no endorsement from Prime Minister Takaichi, and no near-term feasibility for nuclear armament.  

“Not Government Policy”

Tokyo moved quickly to contain the fallout. 

On December 19, 2025, Chief Cabinet Secretary Minoru Kihara reaffirmed Japan’s adherence to its Three Non-Nuclear Principles—no possession, no production, and no introduction of nuclear weapons. 

He stated that government policy remains unchanged and declined to comment on the individual remarks or on any potential disciplinary action.  

Japan adopted the Three Principles in 1967, and they remain a central pillar of national identity and security policy. 

The country is also a non-nuclear-weapon state under the Nuclear Non-Proliferation Treaty (NPT), which it ratified in 1976. 

Withdrawal from the treaty would carry heavy diplomatic, economic, and alliance costs.  

Alliance Strain and Domestic Limits

The remarks come amid renewed debate driven by external pressure and alliance uncertainty. 

Since July 2025, regional tensions have intensified, including Chinese military activity around Taiwan, North Korean missile tests, and Russia’s actions following its war in Ukraine. 

Doubts about the durability of U.S. extended deterrence have grown under the second Trump administration, sharpening internal discussions in Tokyo.  

Prime Minister Takaichi, known for a hawkish posture, hinted in November 2025 that Japan may revisit aspects of its nuclear posture during upcoming security strategy reviews, including policies related to hosting U.S. nuclear assets. 

She later reaffirmed adherence to the Three Principles “for now.” 

Some lawmakers in the ruling Liberal Democratic Party have argued for allowing U.S. nuclear weapons on submarines or other platforms to strengthen deterrence without full nuclearization.  

Public opinion remains divided. 

Polls cited in the source show modest movement toward loosening restrictions on nuclear introduction, but opposition remains strong, particularly among atomic bomb survivors from Hiroshima and Nagasaki and anti-nuclear groups. 

Japan remains the only country to have suffered nuclear attacks, in 1945, a historical constraint that continues to shape domestic politics.