Was he a hero who saved eastern Japan from nuclear catastrophe or an ill-tempered leader who only exacerbated the meltdown crisis at the Fukushima No. 1 plant last March?
That's the critical question surrounding former Prime Minister Naoto Kan, who tried from Tokyo to control the unfolding crisis at the troubled nuclear plant.
On Feb. 28, a private investigation commission published a report on the Fukushima meltdowns that has unleashed media criticism against the short-tempered Kan's "micromanagement" of the crisis response, as described in detail in the 404-page report.
Meanwhile Kan and key aides who were at the prime minister's office have claimed he stopped Tokyo Electric Power Co. from withdrawing all workers from the plant by taking control of Tepco's crisis operations, setting up a joint headquarters on March 15, the climatic day of the crisis.
If everyone had been pulled out, the Fukushima plant would have eventually seen meltdowns of all six reactors and seven spent fuel pools, which could have led to massive radioactive fallout that could have contaminated the whole of eastern Japan, including even Tokyo.
Tepco executives have denied they were trying to withdraw all the workers. Whether the hot-tempered leader's intervention actually saved eastern Japan will remain an open question for the public.
But insiders and the investigation committee would at least agree on one thing — Kan and his aides started intervening because of an apparent lack of preparedness by nuclear officials who were supposed to serve as the main players in managing the crisis, particularly officials at the Nuclear and Industrial Safety Agency.
"Top (nuclear) officials were unable to answer questions from the prime minister. They just turned their face away (from Kan)," Kenichi Shimomura, a long-time friend of Kan's and a councilor at the Cabinet Secretariat, posted on Twitter on March 4.
"This is not an issue that can be solved simply by replacing a prime minister. . . . I trembled with fear to see such behavior of Japan's top nuclear officials," Shimomura said.
Kan has come in for particular criticism for incessantly yelling during the crisis and constantly asking questions about the details of the crisis operations, which almost led to the suspension of the critical seawater injection into the core of reactor 1 on March 12.
The report by the Independent Investigation Commission on the Fukushima No. 1 Nuclear Accident pointed out he attempted to analyze the situation on his own, not trusting nuclear experts and NISA officials at the prime minister's office.
He often used his cellphone to inquire about small details, including the size of backup batteries needed at the plant and ways to transport them to the site, according to the report.
The committee concluded the intervention by the prime minister's office eventually provided little help to mitigate the three meltdowns that occurred.
But the commission also pointed out six other reasons why the politicians at the prime minister's office started directly intervening in the crisis management operations. Kan's personal management style was cited as No. 4.
Among the other six were lack of crisis management manuals for a nuclear disaster, lack of support from bureaucrats, confusion in the chain of command and a deep sense of crisis among top politicians.
The main target of the commission's criticism appears to be systematic failure of the government to prepare for a nuclear crisis, in particular the lack of knowledge and preparedness among top NISA officials and other crisis management bureaucrats at the prime minister's office.
According to the government's nuclear crisis management guideline, NISA chief Nobuaki Terasaka was supposed to serve as the "control tower" to organize crisis operations, the report said.
But Terasaka and other top NISA officials offered few useful proposals to help the top elected officials at the prime minister's office, the commission concluded.
"(The crisis management guideline) won't work unless NISA controls operations in a more integrated way," the report quoted a key bureaucrat at the prime minister's office as saying.
"After all, because of that failure, the prime minister and his aides had no choice but to start engaging deeply" in the response, the unnamed official was quoted in the report as saying.
NISA, the nation's main nuclear regulatory body, has been long criticized for lack of professional knowledge and heavy dependence on Tepco and other utilities in checking the technological details of operations at nuclear plants.
NISA has also been criticized for effectively being a subordinate agency under the Ministry of Economy, Trade and Industry, the main government body that has promoted use of nuclear power. Many top and key NISA officials, including Terasaka, came from METI to hold positions in NISA for short periods of time.
"Overall, government bureaucrats centered on NISA reacted passively and they addressed problems ex post facto. Their presence was weak," the report said.
Meanwhile the commission withheld from drawing a conclusion on whether top Tepco executives, most notably then President Masataka Shimizu, were trying to withdraw all the workers from the plant in the late hours of March 14 through the early hours of March 15.
Tepco officials have claimed they never intended to abandon the plant for good, as feared by the political leaders, and planned to keep the minimum number of workers necessary to control the plant even during the climatic hours from March 14 to 15.
But the commission's report pointed out that Tepco didn't show any number or specific positions of workers who would be retained when it told the prime minister's office that it wanted to withdraw staff from the plant.
It also pointed out that all of the key players at the prime minister's office, including then industry minister Banri Kaieda, Chief Cabinet Secretary Yukio Edano and Kan, believed Tepco was trying to withdraw all of the workers and abandon the Fukushima No. 1 plant for good.
"It's quite difficult to say there is enough evidence to support Tepco's claim" that it was not withdrawing all of the workers, the commission said in the report.