Presently, Japan is sustaining its energy needs through power conservation efforts and an increase of fossil fuel use, but a full‐scale break from nuclear power would have an enormous impact on Japan’s energy policy. It would also have a significant bearing on Japan’s international commitments vis‐à‐vis global warming, and inevitably deal a fatal blow to Japan’s economy and its people’s quality of life.

Any discussion of denuclearisation must be accompanied by a dispassionate consideration of the pertinent issues from the perspective of Japan’s national interests, including the quantitative potential of alternative energies to replace nuclear power over the short, medium and long term. It is dangerous to simply be swept along by the public mood. The broad connectedness of nuclear power means that the impact of denuclearisation would be extensive and it would be extremely difficult to make a return to nuclear power once it has been abandoned.

Japan has an extremely low rate of self‐sufficiency in both energy and food. Its energy self‐sufficiency ratio is a mere 4 per cent — one of the lowest among developed countries. Also, Japan, as an island nation, cannot access electric power transmissions from neighbouring countries. Given these circumstances, nuclear power contributes greatly to Japan’s energy security. At the same time, the remarkable economic development of emerging countries in Asia and elsewhere will likely spur a rapid rise in demand for fossil fuels, making nuclear power all the more important. Another factor is the urgency of worldwide efforts to prevent global warming and the prominence of nuclear power as an energy source that does not produce CO2 emissions. At the September 2009 UN Summit on Climate Change, then Prime Minister Hatoyama announced a target for 2020 of cutting CO2 emissions by 25 per cent from 1990 levels (a 30 per cent reduction from 2005 levels). Although this was a conditional declaration, the figure took on a life of its own as a de facto promise to the international community. Nine additional nuclear reactors would need to be built and operated at a rate of eighty per cent or higher to achieve this.

And the Fukushima accident had major repercussions worldwide. Countries around the globe pushed for more stringent nuclear safety regulations and insisted the IAEA should play a central role in this. But opinions vary on what to do about nuclear power generation itself. Many countries have adopted greater safety‐consciousness, while public sentiment has pressured Germany, Italy and a few other Western countries into steering away from nuclear power altogether. In Japan, as of 6 September, only 12 of Japan’s 54 nuclear reactors were in operation, and restarting the offline reactors upon completion of periodic inspections will be politically difficult. The worst‐case scenario would be a shutdown of all nuclear power generation throughout Japan by next March.

Should nuclear power, accounting for about 30 per cent of Japan’s electric power production, disappear, the likely short-term substitute would be fossil fuels. But this would lead to mounting import costs, more funds diverted to purchase emissions credits to cover greater CO2 emissions, and higher power generation costs. Forecasted rises in fossil fuel prices would only exacerbate the problem. Natural energy such as wind and solar power could become available over the medium and long term, but Japan has been one of the slowest among developed countries to pursue renewable energy, currently representing about 1 per cent of its total power generation.

Dependence on natural energy will create problems relating to the reliability of supply, quantitative expansion, energy economy, and the quality of the power generated. Natural energy might be useful as a dispersed and supplementary power source but not as a primary source of electricity for such a large economy; and unwarranted changes in energy policy will only bring about major disruptions to Japan’s economy.

Furthermore, what do proponents of denuclearisation intend to do about the array of international agreements Japan has entered into, including for the export of nuclear power plants? What about the de facto international restrictions on CO2 emissions put in place to prevent global warming? These issues will affect the international community’s trust in Japan. Abandoning nuclear power would involve withdrawing from the ‘nuclear fuel cycle’, one of resource‐poor Japan’s most important energy policies. With the nuclear fuel cycle dependent on accumulated experience and trained personnel, any withdrawal would make it extremely difficult to restart. Evidently, careful deliberation is needed to assess the wisdom of withdrawal.

I believe that an objective look at Japan’s geopolitical situation and the scale of its economy, as well as quantitative assessments of the issues concerned, will show that abandoning nuclear power is an unreasonable choice for Japan. The most practical measures are to continue the use of nuclear power while conducting thorough safety reviews. In parallel, natural energy sources should be actively developed and the best mix of all forms of energy sought. Denuclearisation is not a path which Japan should go down.

Tetsuya Endo is Senior Adjunct Fellow at the Japan Institute of International Affairs (JIIA) and was formerly Vice Chairman of the Japan Atomic Energy Commission.