In Hiroshima, in early August, the sun is so strong and bright that it fries the sky a shimmering white that hurts your eyes if you stay out too long. This was the baking place where, 67 years ago this week, brilliant American scientists and brave American airmen exploded an atom bomb that seared the sky and instantaneously wiped much of Hiroshima and tens of thousands of people from the face of the earth.
Yet, today, powerful politicians in Japan are hard at work trying to scrap or smash article 9 of the country's constitution - which renounces war - and some of them want to go all out to build a Japanese nuclear weapon.
What are they thinking about? It beggars belief that a country that has suffered so much, first from being - so far - the only victim of nuclear war, and then from bungling over the use of peaceful nuclear energy, should be contemplating building nuclear weapons.
It is almost a game of Chinese roulette. Japan does not know how to cope with the rise of an increasingly assertive and muscular China. It is also obviously concerned about nuclear-armed North Korea.
But Chinese roulette is more suicidal than the Russian version: if Japan built nuclear weapons for first-strike capability against an overbearing China, it would be committing national suicide; second-strike, or retaliatory, capacity might be too late if China had done its job properly. Using nuclear weapons against North Korea, whatever the provocation, seems unthinkable.
That is without considering the suicidal economic costs. France and Britain have discovered that keeping up with the latest nuclear weapons technology is prohibitively expensive. For heavily indebted Japan, it could be the final straw to economic ruin.
Any decision to build nuclear weapons would be a red rag to China, far more serious than the Tokyo government or Japan buying the disputed Senkaku, or Diaoyu, islands. Even so, hawkish Japanese politicians, including Tokyo governor Shintaro Ishihara, claim that flaunting the bomb option will give Japan greater diplomatic clout.