During his visit to New Delhi last week, Prime Minister Shinzo Abe and his Indian counterpart Narendra Modi agreed in principle on a civil nuclear cooperation pact that would pave the way for export of Japan's nuclear power plant technology to India. It will be Japan's first such deal with a country that has not signed the Nuclear Nonproliferation Treaty. In working out its further details, the government needs to ensure a clear mechanism to prevent India from using the technology provided by Japan to enhance its nuclear weapons capabilities. This is Japan's duty as the only country in history to suffer nuclear attacks.

Japan has so far refrained from signing a civil nuclear cooperation pact with countries that are outside the NPT regime. Such an agreement with India, a de facto nuclear weapons power, is tantamount to Tokyo accepting possession of nuclear weapons by a country that is not a party to the NPT, representing a major shift in Japan's nuclear policy. It may compromise Japan's position of calling on North Korea, which has withdrawn from the NPT regime, to end its nuclear weapons program. The pact would have the effect of further reduce India's incentive to join the NPT regime. One wonders whether the Abe administration has seriously considered these effects.

The root of Japan's talks with India for a civil nuclear pact goes back to a proposal made in the late 2000s by U.S. President George W. Bush to change the rules of the Nuclear Suppliers Group (NSG), a multinational body designed to control the export of nuclear apparatuses and technology to ensure nuclear nonproliferation. Behind the proposal was the Bush administration's desire to strengthen the United States' strategic ties with India. Although the NSG, whose members include the U.S., Russia, Germany, France, Britain, Canada and Japan, had prohibited civil nuclear cooperation with India because of its nuclear explosion test in 1974, the group in 2008 granted a waiver to India from its rules. Japan was initially cautious about the change but eventually succumbed to pressure from the U.S.