Is it possible that something as awful as the nuclear holocausts at Hiroshima and Nagasaki was -- in the cold, long view of historical time -- a positive good, a lucky break for the human race?

To even find that question in my mind makes me back off and check my sanity and my humanity. How is that possible? How can anyone who loves someone else think such a thing? But I've been reading much in the past year about the juncture of World War II and the Cold War and this question keeps coming back to me, more clearly each time.

Hiroshima. Nagasaki. Even today, more than 60 years later, every time someone somewhere in the world gets mad at America, those two names rank among the taunts they spit.

In vain do Americans protest that people who do so ignore context and act as though Japan was peacefully minding its business when U.S. bombers just sailed over and dumped two atomic bombs on it.

In vain, too, do we point out that the firebombing of Tokyo on the night of March 9-10, 1945, killed more people than either Hiroshima or Nagasaki. (As did, for that matter, the Japanese "Rape of Nanking" in 1937.) Or that the Allied air raids over Dresden in 1945 killed more than both combined. "You guys burnt the place down, turned it into a single column of flame," wrote Kurt Vonnegut Jr. But no one taunts Americans with "Dresden," or "Tokyo."

The Germans, in a decade of recovering their forgotten history, have noticed this, too. Writing of the Hamburg firebombing of 1943, Jörg Friedrich writes (Der Brand: Deutschland im Bombenkrieg, 1940-1945) "The approximately 40,000 fatalities in the July 1943 campaigns are, together with those in Dresden, Tokyo, Hiroshima, and Nagasaki, emblems of the most extreme kind of violent warfare ever inflicted upon a creature. Not because of the streams of blood spilled, but rather because of the way that living beings were erased from the world with a deadly wind."

But they are not the same. They are not felt together in the collective human mind, whatever Friedrich thinks. If you don't believe me, go to an anti-American protest anywhere in the world -- Tehran or San Francisco -- and read the signs.

I suspect even the people who argue the numbers sense the difference. Hiroshima was much more than Dresden with different statistics. If the firebombings saw the old weapons used to their maximum effect, the atom bombs saw the dawn of an utterly new day of death.

Wars have been getting bigger and more destructive since the start of history, as technology advances. The estimated casualty rate of the two world wars was 300 times greater than that of the Peloponnesian War 24 centuries earlier. For years the directors and technicians of the Manhattan Project had been working on a new and terrible weapon. They called it a "superbomb." It was meant to be a military weapon, used to win a war. It was meant to be the next step in the long march that goes back at least to Athens and Sparta.

But it wasn't. The atomic bomb's power increased lethality by a factor of millions. To a human mind, mumbers that big are inert and abstract until you see the physical evidence of them. It wasn't till people saw it, and saw what it did to a city, that this sank in. Even setting one off in a desert didn't have quite the necessary impact. It made a big bang, but the place was wasteland before and wasteland after. To know its power we had to see what it did to a city full of living human beings.

That's almost intollerably cruel, but that's how humans are made. Whether we're from Missouri or Moscow. You have to show us.

The impact of it on human minds, the dislocation, was immense.

"A bright light filled the plane," wrote Lt. Col. Paul Tibbets, the pilot of the Enola Gay, the B-29 that dropped the first atomic bomb. "We turned back to look at Hiroshima. The city was hidden by that awful cloud ... boiling up, mushrooming." For a moment, no one spoke. Then everyone was talking. "Look at that! Look at that! Look at that!" exclaimed the co-pilot, Robert Lewis, pounding on Tibbets's shoulder. Lewis said he could taste atomic fission; it tasted like lead. Then he turned away to write in his journal. "My God," he asked himself, "what have we done?" [Newsweek, July 24, 1995]

At twelve o'clock, we flew over Hiroshima. We ... witnessed a site totally unlike anything we had ever seen before. The centre of the city was a sort of white patch, flattened and smooth like the palm of a hand. Nothing remained. The slightest trace of houses seemed to have disappeared. The white patch was about two kilometres in diameter. Around its edge was a red belt, marking the area where houses had burned, extending quite a long way further, difficult to judge from the airplane, covering almost all the rest of the city. It was an awesome sight ....

Truman made the key decision to withhold the atom bomb from the American military's arsenal, even at the danger point of the Cold War when the West was most vulnerable. He insisted the new bomb would be used, if at all, not at the discretion of generals, but under the highest and tightest civilian control.

If the bomb had never been used before then, if it had remained, in most people's mind, an abstract weapon, a much bigger version of the World War II "blockbusters," would that choice have been made? And if it hadn't, would the temptation to use the bomb as a tactical or battlefield weapon in Korea, or Vietnam, or Cuba, been irresistable to some American president or general?

It never came to that. In part, I believe, because we had seen it once.

And thank the gods. For the atomic weapons America used in Japan were mere bottle rockets compared to the thermonuclear H-bombs of just a few years later. The necessary experience had been accomplished at the start of the nuclear weapons era when -- as chilling as it is to say this -- the harm was as minimal as it could be.

This does not validate anyone's president or nation. If Truman's decision to bomb Japan twice in 1945 was defensible, and I believe it is, the evidence of it lies elsewhere. This was an utterly unforeseen consequence of that decision. But it may have saved the world.

It also may account, in small part, for one of the most remarkable, and overlooked, facts of modern history. For five years or more the U.S. and its allies Britain and Canada had sole possession of nuclear weapons. They knew the secret would not keep. But they knew that, while it did, they had the power to arrange the world to suit themselves and to dictate policy to every nation. They did not do so. They never took a step in that direction. It was universally understood that they would not do such things. Of how many other peoples and nations would that have been true?