Japan Saturday (August 6) marked the 60th anniversary of the atomic bombing of Hiroshima - the first time nuclear weapons were used in warfare. The American aerial attack, followed three days later by a plutonium bomb dropped on Nagasaki, prompted the Japanese to surrender and ended World War II. For Japan - the only victim of nuclear war - the attacks scarred the national psyche - creating what many call a "nuclear allergy." But, six decades later Japan has become a nuclear energy nation and taboos concerning possible nuclear weapons are receding.
Each year on August 6 in the Hiroshima Peace Park at precisely 8:15 a.m., an invocation begins for silent prayer; followed by a tolling bell marking the exact moment an atomic weapon was dropped from above Japan's industrial city.
At Hiroshima and Nagasaki, more than 100,000 civilians were killed outright. Hundreds of thousands of survivors suffered radiation poisoning - many succumbing over the next weeks, months or even years.
Hiroshima and Nagasaki stand as testaments to the horrors of atomic warfare and propelled a devastated Japan to become known as the Switzerland of Asia - a pacifist and strongly anti-nuclear nation. Since 1956, it has been national policy not to possess, manufacture or allow nuclear weapons in the nation.
By that time, Japan, however, was snugly under the U.S. nuclear defense umbrella as a new ally of Washington. And that alliance included secret agreements - in defiance of Japanese policy - overtly or tacitly permitting American nuclear weapons on outlying Japanese islands or on U.S. warships in Japanese ports.
Japan went on to become a nuclear energy power, building dozens of plants to provide electricity for the resource-poor nation.
And by the 1970s, Japan was secretly examining whether it made sense to have its own nuclear weapons.
"Each time it came to the same conclusion that this was not a good option for Japan," explains Senior Research Fellow James Przystup at America's National Defense University. "Japan is a very small country that has absolutely zero strategic depth. And in a nuclear exchange that's not the kind of position you want to be in."
More recently, however, that thinking is changing. Policymakers in Tokyo are concerned about new possible threats from North Korea's ballistic missile and nuclear weapons programs and China's rising power.
So now the idea of creating a nuclear defense - which was taboo just a decade ago - is being debated in mainstream political, academic and media arenas.
"If worse comes to worst and North Korea takes the plunge into nuclear testing, even louder calls are likely to be made in Japan to arm ourselves with nuclear weapons as a deterrent. This cannot be ignored," says Kazuhiro Haraguchi, a member of Parliament from the opposition Democratic Party.
To many Asia watchers, such as Balbina Hwang at the conservative Heritage Foundation in Washington, the North Korean question will probably be the catalyst for a possible nuclear arms race in Asia.
"If it is not managed well by the United States then, I think, then we are in for a very dangerous future," she said. "I do see a great potential for an arms race. In the classic sense, buildup of conventional arms, but, of course, if you add North Korea, into the mix, now we're talking about an arms race with nuclear weapons."
Ms. Hwang says Washington is tacitly acknowledging that a nuclear-armed Japan is a possibility, dropping hints to Beijing that if it does use its influence with Pyongyang to curb it's atomic ambitions, the United States might not be able to prevent Tokyo from going nuclear.
"That, I think, is a very dangerous game to play," she said. "I think that China probably has those latent fears anyway. I don't think the United States needed to dangle it."
But some analysts believe it would take much more than a North Korean nuclear test to prompt Japan to go nuclear.
"I don't think that a North Korea [nuclear] test or a fully declared status would be the trigger for Japan going nuclear," says Weston Konishi, who is with the policy group, Mansfield Foundation, in Washington. "What I'm talking about is more a scenario in which the U.S.-Japan alliance starts to disintegrate. In other words, if the U.S. nuclear umbrella were to some day disappear, then Japan would go nuclear."
All analysts agree that is not likely to happen anytime soon with the alliance between Tokyo and Washington as strong as ever.
Japan did have a nuclear weapons program once before. That was during World War II. Back then it had insufficient resources and time to make progress. These days, Japan would not face such difficulties. It has the raw materials, technology, and money to develop nuclear weapons. What is still lacking is a national consensus.
So far indications from national polls show that for the time being, most Japanese still believe that the long-standing national "nuclear allergy" will keep Japan immune from ever crossing from atomic victim to possessing its own nuclear arsenal.