Former Top SDF Commander Urges Review of Non-Nuclear Policy

このページを日本語で読む

As China, North Korea, and Russia deepen military cooperation and expand their nuclear arsenals, how should Japan prepare?

Koji Yamazaki, former Chief of Staff, Joint Staff, argues that Japan should reconsider its Three Non-Nuclear Principles. He was the only former Self-Defense Forces (SDF) officer to serve on the government's expert panel reviewing Japan's National Security Strategy and the three key national security documents.

In this interview, he discusses nuclear deterrence and his vision for the future of the Self-Defense Forces.

You called for a review of Japan's Three Non-Nuclear Principles during the government's expert panel discussions. What did you mean by that?

I believe Japan needs a national debate on strengthening deterrence to ensure that nuclear weapons are never used against our country.

Russia has repeatedly threatened to use nuclear weapons against Ukraine, while China, North Korea, and Russia have lowered the threshold for nuclear coercion and the potential use of tactical nuclear weapons. The nuclear threat has become increasingly real.

Given this security environment, I believe the third principle—not permitting the introduction of nuclear weapons into Japan—should be replaced with a principle of not allowing nuclear weapons to be used against Japan.

What would be the significance of revising the principle against introducing nuclear weapons?

I am concerned that Japan and the United States are not currently holding sufficient discussions about how US nuclear forces would be employed.

Revising the principle against introducing nuclear weapons would allow discussions on the circumstances under which US nuclear weapons could be brought into Japan. It would also make it possible to establish decision-making procedures and develop joint operational plans between the Self-Defense Forces and US forces.

We are no longer in a security environment where we can simply say, "The government of the day will decide when an emergency arises." We need to anticipate potential contingencies and make every possible preparation during peacetime.

Some in Japan advocate either acquiring nuclear weapons or establishing a nuclear-sharing arrangement with the United States. What is your view?

Free debate should be encouraged, but I oppose Japan acquiring nuclear weapons.

If Japan—the only country ever to have suffered atomic bombings in war—were to become a nuclear power, it could trigger a chain reaction of nuclear proliferation around the world.

As long as Japan faces a nuclear threat, we must strengthen the credibility of US extended deterrence. At the same time, we should never abandon the long-term goal of eliminating nuclear weapons.

That said, any discussion of nuclear sharing should come only after reconsidering the principle against introducing nuclear weapons.

Do you believe Japan should introduce nuclear-powered submarines?

Their advantages cannot be denied. Nuclear-powered submarines can operate at high speeds for extended periods, giving them a significant advantage when conducting operations across the vast Pacific Ocean.

However, introducing them would require a comprehensive management system extending far beyond the Maritime Self-Defense Force, including nuclear safety management and personnel training.

We must also consider public opinion, procurement costs, and personnel availability. The government should examine the issue from every angle, consult experts, and make a decision as a nation.

How do you see Japan's future security environment?

It is likely to become even more challenging. We must strengthen both the Self-Defense Forces and Japan's overall defense posture so that they are truly capable of responding to national emergencies. We also need to improve our ability to sustain prolonged conflicts and adapt quickly to new forms of warfare.

Which areas should Japan strengthen?

Ukraine has been able to withstand a prolonged war with Russia largely because the government and society have worked together to maintain essential services.

In a contingency, critical infrastructure—including energy, communications, transportation, healthcare, and government services—could all come under attack.

The challenge is not only to strengthen the capabilities of the Self-Defense Forces, but also to enhance the resilience of the nation as a whole.

With Japan's population continuing to decline, what should the Self-Defense Forces look like in the future?

The Self-Defense Forces should focus on missions that only military personnel can perform, such as command and control and combat operations.

Support functions—including logistics, maintenance, training, and base operations — should be outsourced to the private sector.

Today, the boundaries between military and civilian roles, as well as between the front lines and the rear, have become increasingly blurred. We should build a system that enables the Self-Defense Forces and the private sector to work together during contingencies.

What about the functions shared by the Ground, Maritime, and Air Self-Defense Forces?

Last March, the Joint Operations Command was established to provide unified command of the Ground, Maritime, and Air Self-Defense Forces.

To further strengthen joint operations, we should integrate transportation, logistics, maintenance, and other functions wherever possible, and consider establishing new functional commands.

We also need to standardize equipment across the three services. Greater standardization of parts would improve efficiency.

Profile: Koji Yamazaki

Born in 1961 in Nishikatsura, Yamanashi Prefecture, Koji Yamazaki graduated from the National Defense Academy and joined the Ground Self-Defense Force. He later served as Commander of the Northern Army and Chief of Staff of the Ground Staff before being appointed Chief of Staff, Joint Staff in 2019. He retired from the Self-Defense Forces in 2023 and is currently a Senior Fellow at the Sasakawa Peace Foundation.

Interview by Shusuke Takenouchi, The Sankei Shimbun

このページを日本語で読む