OSAKA – With North Korea’s substantial nuclear arsenal and improved intercontinental ballistic missile capability, the world has no choice but to tolerate its illegitimate possession of nuclear weapons.

Pyongyang will never give up its nukes, which it considers essential for regime survival. Nor can they be eliminated without a massive pre-emptive attack that would invite catastrophic counterattacks against both South Korea and Japan.

The United Nations Security Council has just passed a resolution to impose additional, more stringent sanctions on North Korea. But these penalties fall short of a full oil embargo and other “super sanctions” that might immediately jeopardize the regime’s survival and force Pyongyang to abandon its nuclear weapons. The country is believed to possess not only adequate oil reserves for one year but also limited oil refining capability.

China disapproves of super sanctions. But following the recent series of North Korean provocations, it has assented to additional, severer measures and it may enforce existing measures more stringently. China has long supplied most of the oil and grain needed by North Korea to maintain it as a strategic buffer vis-a-vis the United States and prevent the regime’s collapse, which would entail a massive inflow of North Korean refugees. Besides, China itself now faces a significant nuclear threat from North Korea. After all, the effective range of Pyongyang’s newly operational nuclear missiles covers northern China, including the capital, Beijing.

Russia doesn’t want to cooperate in imposing super-sanctions either. It has supplied substantial gasoline and jet fuel to North Korea, as if to offset China’s reduction of these vital commodities in response to U.S. President Donald Trump’s demands. Evidently, Russia has become Pyongyang’s primary backer while striving to deal with the hostile U.S. establishment that has continued intense offensives centered on the Crimea annexation issue and the “Russiagate” interference in the U.S. presidential election last year. In fact, Russian President Vladimir Putin has made a series of statements against both military options and super sanctions vis-a-vis North Korea, instead suggesting that de facto nuclear arms control negotiations be pursued with the country.

Pyongyang will take advantage of this U.S.-China-Russia disunity and proceed with its drive to develop nuclear weapons. As a result, Japan will face an existential threat within the next year or two, especially after Pyongyang develops ICBMs that can attack the continental U.S. This means Japan will soon be unable to rely on U.S. extended nuclear deterrence due to significant doubts about Washington’s commitment to nuclear retaliation.

Inadequate missile defense

At present, Japan’s two-tier missile defense system is hardly adequate. It is designed as a simple theater missile defense that cannot provide a complete shield against North Korea’s sizable number of nuclear missiles, particularly now due to the most recent technical leaps in performance. Nudged by the profit-seeking U.S. military-industrial complex, Japan is striving to acquire Aegis Ashore, a ground-based variant of the warship-based system, as a major supplement, but active defense will never solve the essential problem. Only the promise of punishment by nuclear retaliation can deter North Korea.

Thus, when the sense of crisis is heightened, Japan will most probably be driven to go nuclear, leading to self-reliance and strategic independence involving the abrogation of the alliance with the U.S., its sole security guarantor.

Alternatively, after suffering a nuclear attack, Japan would surely terminate the alliance, necessarily opting to be self-reliant and strategically independent by going nuclear. In either way, the U.S. will lose Japan, which is vital in maintaining its global military dominance in light of forward deployment, logistics and other crucial functions.

Japan follows an internally conflicted non-nuclear policy, while simultaneously facing a dilemma. Out of its unique historical experience of the atomic bombings of Hiroshima and Nagasaki, the country is committed to nuclear disarmament while supporting the Non-Proliferation Treaty as a non-nuclear power. As a result, Japan has consistently taken the national policy of no possession, production or introduction of nuclear weapons. Nonetheless, it relies on U.S. extended nuclear deterrence for national security.

Nuclear sharing

To prevent Japan from becoming a wild card, the U.S. should adopt a policy of “nuclear sharing” with Japan, emulating the concept as it is used in the NATO framework. Member countries without nuclear weapons of their own are included in the planning for the use of nuclear weapons by NATO, in particular providing for the armed forces of these countries to be involved in delivering the weapons in the event of their use.

The U.S. should plan together with Japan during peacetime the use of tactical nuclear weapons, and provide nuclear-armed Tomahawk cruise missiles for delivery by Japan’s large fleet of conventional submarines in the event of their use. These missiles should be stored in a U.S. base in Japan during peacetime. The U.S. should control them with a security device to prevent unauthorized arming and detonation.

Nuclear sharing would require Japan to introduce U.S. nuclear weapons on its soil, but enable the U.S. to avoid a direct challenge against Japan’s non-nuclear policy by equipping U.S. forces in Japan with the weapons. This is a necessary evil given the current turbulence in the regional security environment. Japan would neither have to possess nor produce nuclear weapons, enabling continued observance of its obligations under the NPT. This approach would reinforce the political base of the pivotal bilateral alliance.

Masahiro Matsumura is a professor of international politics and national security at St. Andrew’s University (Momoyama Gakuin Daigaku) in Osaka.