Japan doesn’t have a nuclear bomb and doesn’t plan to develop one, but the country has so much uranium and plutonium stockpiled at home and abroad that making one wouldn’t take long at all. This “bomb in the basement” is seen by some Japanese leaders as an important deterrent against China and North Korea. Indeed, the Abe administration plans to open up a new “breeder” reactor that will produce even more plutonium than the country’s (currently offline) nuclear power system can handle. For China and even South Korea, this is an uncomfortable signal of Japan’s secret strength, prompting both countries to find ways to stay on the front foot.“China seems to take the basement bomb seriously,” Robert Windrem reports in a lengthy and worthwhile read over at NBC News. Beijing is even more worried about a new fast-breeder plutonium reactor scheduled to open in Rokkasho in October. Breeder reactors produce more plutonium than they consume. Rokkasho will add to Japan’s already substantial stockpile of nuclear bomb-making material, which of course isn’t being used to make a bomb but could be. Japan has 9 tons of weapons-grade plutonium and 1.2 tons of enriched uranium stashed around the country, and a further 35 tons of plutonium stored in France and the UK. That’s enough for 5,000 nuclear bombs. Rokkasho will produce 8 tons of plutonium a year, which is enough for 1,000 Nagasaki-sized weapons.“The hawks [in Japan] love nuclear weapons, so they like the nuclear power program as the best they can do,” a nonproliferation expert told NBC. “They don’t want to give up the idea they have, to use it as a deterrent.” But beyond deterring China, the stockpile also spurs South Korean interest in developing its own nuclear capabilities. According to a poll last year, 66 percent of South Koreans support the development of a nuclear weapons program. Mostly this is a reaction to North Korean belligerence, but relations with Japan are deteriorating quickly.This is an area where US leadership and mediation is needed. South Korea and Japan are barely on speaking terms at the moment. That’s a situation that could get worse, especially if the Obama administration fails to work out the kinks in the Pivot.