Since spring, former Prime Minister Junichiro Koizumi has become increasingly vocal in his opposition to nuclear power. Though he decided Japan should abandon atomic reactors after the Great East Japan Earthquake set in motion the Fukushima crisis, he was already retired from politics. The mass media paid no attention.

Then he sat for an interview with the Mainichi Shimbun in summer and described a trip he took to Europe, at his own initiative and in the company of several nuclear industry executives, to inspect the Onkalo nuclear-waste repository in Finland and the situation in Germany, which has moved away from atomic energy. Despite the presence of men whose job it was to convince him otherwise, he returned even more resolute in his belief that Japan must reject nuclear.

The response has been divided along predictably ideological lines. Politicians who are against the ruling Liberal Democratic Party’s plan to reopen as many plants as possible are delighted to have the former president of the LDP on their side. Since Koizumi is one of Prime Minister Shinzo Abe’s mentors it might be bad form to criticize him, but last week he called Koizumi’s idea “irresponsible” on TV Asahi.

The official party position seems to be to ignore him. Chief Cabinet Secretary Yoshihide Suga remarked that like any citizen, Koizumi “can say anything he wants,” though Economic Revitalization Minister Akira Amari told reporters that Koizumi’s stance demonstrates that he’s not thinking about what he’s saying.

All this beating around the bush hardly mattered to the average person, but on Oct. 20 Koizumi gave a lecture in Kisarazu, Chiba Prefecture, and invited TV cameras to record it. That night, every station showed clips of the speech and suddenly the ex-premier couldn’t be ignored, since the general public could see for itself that he is adamant in his opposition to nuclear energy, which he supported when he was a lawmaker. The speech itself was nothing special, but the fact that he was making it — and making a big deal of it — was.

Still, it wasn’t as notable as the letter Koizumi wrote earlier in response to a Yomiuri Shimbun editorial that slammed his position. Koizumi’s angry missive picked apart each complaint made by the paper, which backs the LDP’s plan to restart reactors. The Yomiuri called Koizumi’s belief in Japan’s ability to develop renewable energy “optimistic and irresponsible,” and reiterated all the arguments of the pro-nuclear camp — that nuclear is cleaner and cheaper; that thermal is bad for consumers and the environment.

Koizumi’s rebuttals were flimsy, but his main assertion — that Japan cannot maintain a nuclear-power industry if it has no place to put its waste — was attacked by the paper with sloppy logic. The Yomiuri dismissed Koizumi’s concern because the short-sightedness of not providing a nuclear waste repository “is the fault of politics,” of which he was at the center for many years. Koizumi has no right to complain about a situation he had a hand in creating.

In his famously casual way, Koizumi waved off the criticism by admitting he didn’t develop a plan for storing nuclear waste when he was prime minister, but that doesn’t mean “a person can’t correct himself.” In any event, the Yomiuri professes the same unfounded optimism it accuses Koizumi of advancing. The paper says the problem of finding a place to put nuclear waste will eventually be solved “by political means,” but there is no indication that anyone in Japan will ever allow the government to bury it in their backyard.

Political pundit Yoshiya Kobayashi, quoted by online news magazine Zakzak, was flabbergasted by the letter, saying that while Koizumi has firmly stated he has no intention of running for office again, he appears to be even more of a henjin (eccentric) than he was when he was a legislator. Koizumi is “pushing his opinion” even though he gains nothing personally from it. This is a first for Japan: a political figure who not only undergoes a change of mind in public, but tries to make a difference after giving up the political power to do so.

Koizumi’s public challenging of a major daily’s editorial position is something else no Japanese politician of his stature, retired or active, has done before, and the backlash was immediate. Isao Iijima, Koizumi’s closest aide for 35 years, wrote an article for the weekly Shukan Bunshun in which he implies his former boss never had an original idea in his life. Most politicians are facilitators, not idea men, and whatever you think of his pet privatization project, Koizumi was good at selling it, what with his knack for communicating policy in simple, down-to-earth language. Iijima’s article is transparently self-serving, since he now works for the LDP as a cabinet adviser. Like the Yomiuri, he believes that all the problems with nuclear power will be solved over time through “political efforts.”

What might be making the LDP nervous is not so much Koizumi’s activism but rather the effect it could have on his son, Shinjiro, the party’s rock star. Shinjiro is genuinely liked by the public, which is why he volunteered for the position of reconstruction minister, a job nobody else in the LDP would touch. Abe is in his debt, because people in the disaster-affected areas think that if the LDP is sending its most popular politician to Tohoku, it means the government is serious about rebuilding.

That places him in an awkward position, since the media wants to know his thoughts on his father’s genpatsu zero (no nukes) advocacy. An article in Yukan Fuji quoted him as saying that while he must follow the party line, he wants to hear what his father has to say.

Earlier, Mainichi reported that he had answered some journalists’ query about Koizumi Sr. with the observation that politics is a struggle between “the ideal and reality,” and no one wants a politician who “ignores people’s hopes and dreams.” Of course, many of his supporters hope that the nuclear reactors don’t reopen — but maybe it’s just a dream.