As political bookends go, Junichiro Koizumi and Taro Kono make quite a pair. Will history show that both men stood on either side of Shinzo Abe losing his prime ministership?

Former Prime Minister Koizumi, 76, was Abe's mentor way back when, championing Abe to replace him in 2006. Kono, 55, is Abe's current foreign minister — and a potential rival. What joins them today is a stance against Abe's slavish devotion to nuclear power. In the space of one week, Koizumi and Kono both called out Abe for antiquated energy ideas wedded more to 1985 thinking than where Japan could find itself in 2025.

Koizumi leads a group of anti-nuclear activists demanding an "immediate halt" to Tokyo's addiction to reactors to prevent another Fukushima-style disaster. On Jan. 10, they warned of the "costly" nature of atomic power, which the so-called nuclear village argues is cheap, clean and safe. Yet Koizumi's pitch is also about economics: Winning Japan a big piece of the renewable energy boom could, unlike Abenomics, rekindle Japan's innovative mojo.