TOKYO -- Sixty years after the horrors of Hiroshima and Nagasaki, the Japanese are beginning -- with a gentle nudge from Washington -- to talk openly about the long-forbidden subject of nuclear weapons.
The post-World War II pacifism under which Japan's military is known as a "self-defense force" remains strong. But the rise of China and North Korea's nuclear ambitions have spurred what is referred to here as "active pacifism," or a more pragmatic line on defense.
Talk of a nuclear Japan has, in some cases, been broached by American officials.
The new U.S. ambassador to Japan, Thomas Schieffer, had barely settled into his office in June when he told reporters: "If you had a nuclear North Korea ... it seems to me, that increases the pressure on both South Korea and Japan to consider going nuclear themselves."
Two years earlier, Vice President Dick Cheney was quoted in the Asahi Shimbun newspaper saying a nuclear-armed North Korea could force Japan to "consider whether or not they want to readdress the nuclear issues."
Japan will likely choose to remain as "America's strategic dependent," wrote Robyn Lim, professor of international relations at Nanzan University in Nagoya, in the July 19 issue of the Jamestown Foundation's China Brief.
But, he said, "Because of the growing sense of threat from North Korea's dangerous nuclear ambitions, it is no longer taboo to talk about nuclear weapons in Japan."
For 34 years, Japan's nuclear-weapons policy has been based on three principles known as the "sangensoku," under which the country renounces the right to own or produce nuclear weapons or allow them on Japanese territory.
But Tokyo foreign-affairs columnist Yoichi Funabashi says a debate has begun within Japan's defense-policy community on whether to amend the sangensoku to afford free passage to nuclear-armed U.S. warships.
Shinzo Abe, a rising political star and grandson of former prime minister Nobusuke Kishi, has gone further, arguing that there is nothing unconstitutional about possessing small, strategic nuclear weapons. Mr. Abe is considered a leading contender to replace Prime Minister Junichiro Koizumi, whose term ends in 2006.
Similarly hawkish pronouncements have been heard from influential opposition leader Ichiro Ozawa, who told an audience in Fukuoka in 2002: "It would be so easy for us to produce nuclear warheads. We have plutonium at nuclear-power plants in Japan, enough to make several thousand such warheads."
Japan's burgeoning stockpile of plutonium already is drawing suspicion from its Asian neighbors. The country is the world's third-largest user of nuclear power after the United States and France with about 50 uranium-fueled nuclear reactors.
Next year, a massive $20 billion plutonium-reprocessing plant will open at Rokkasho-mura in the northern part of the main island, Honshu, marking an expansion into a branch of nuclear energy that is so complex, risky and costly that few nations have attempted it.
Anti-nuclear organizations charge that Rokkasho-mura -- the only such facility in a declared non-nuclear state -- dangerously increases the risks of global proliferation.
"Whereas Nagasaki was destroyed by [12 pounds] of plutonium, Japan itself currently has nearly [100,000 pounds] and plans to have a lot more," said Shaun Burnie, a spokesman for Greenpeace International. "We believe Japan's program is unjustified and poses a major proliferation threat to this region."
Other Japanese experts scoff at the near-term possibility of a nuclear-armed Japan.
"The Hiroshima-Nagasaki legacy is so profound," said Mr. Funabashi, that "less than 10 percent" of the Japanese public supports nuclear weapons and to advocate their use would be political suicide.
Similarly, a government defense expert who spoke on the condition of anonymity said any speculation that Japan might adopt nuclear weapons was "baseless."
The expert suggested that the United States was raising the prospect simply to pressure China into working harder for a nuclear deal with North Korea.