It reports that at the June 28th summit between Japanese Prime Minister Taro Aso and Korean President Lee Myung Bak, Aso asserted that further escalation of the North Korean nuclear issue could encourage stronger calls in Japan for the country to obtain its own nuclear weapons.
Aso apparently brought up this possibility as an example of why China should be more helpful in resolving the problems with North Korea. And in case this veiled threat was not clear, the Asahi quoted a willing Japanese government source as saying "the tone was not that Japan would go nuclear" and the South Koreans did not offer strong objections.
The date of Mr. Aso's remarks caught my attention. Aso's "what if" diplomacy, as the Asahi reporter observed, seemed timed to "take advantage" of the nuclear armament discussions appearing in Tokyo at the time. As you may recall, Amb Ryohei Murata revealed Japan's nuclear "secret" with the U.S. to the Mainichi on June 29th.
Thus, it is highly unlikely that Amb Murata was merely an old man unburdening himself of memories and lies. There was a strategy to his madness, after all.