Many take the month as an opportunity to flee hot, crowded metropolises like our own. Beaches fill, cities empty. The heat makes it hard to think, so why try?

I too think of cities emptying in the heat - but from nuclear heat, and the miniature suns that burst over Japan in August 1945.

The atomic explosions whose anniversary occurs this week ended World War II. Though scores of thousands died in Hiroshima and Nagasaki, surely the bombs saved millions who would have perished in the planned invasion of Japan.

Not just Americans or Japanese would have died without these bombs. What would have happened in occupied Hong Kong or China if war had dragged on for another year or more? Millions of Chinese had already perished. How many more would have died?

Would we have this dramatic city to holiday from? With every possible resource going into an all-out war against suicidal defenders on Japan's main islands, the Allies could not have spared much thought to Hong Kong.

Without the bombs, we might have lost much more. Had the war dragged on, and seeing millions dying in their invaded homeland, what would labs like Unit 731 have done? Unit 731 was a laboratory run by the Japanese army in China where toxins and plagues were tested for effectiveness on prisoners and villagers. If effective, they were to be deployed as a means to depopulate the countryside of its inhabitants as well as for weapons of war.

These were truly weapons of mass destruction, meant not to shorten a war and save lives but to massacre millions of innocents simply because they were of the wrong ethnicity, nationality and religion. Might these desperate men have managed to unleash a massive plague if war had continued?

Records show that Unit 731 had already tried to spark epidemics. They failed because they ran out of time after the atomic bombs convinced Japan's emperor further fighting was futile.

As we struggle today to prevent a bird flu or pig-borne plague breaking out in our region, the thought humans would deliberately spread mass death, for whatever reason, under whoever's orders, repels. But as the terrorist acts of destruction in New York, Bali, Madrid, London and atrocities in Iraq demonstrate daily, there are many who seek to inflict mass death rather than prevent it.

There are those today, just as in the 1940s, who seek to destroy whole civilizations for being of different races and beliefs.

These people do not take holidays. They think of this anniversary not as a warning of the horrors mankind can inflict. They see the surrender of Japan as evidence that destruction can produce compliance.

Some, fearing mushroom clouds over Washington or London, have justified everything and anything from the invasion of Iraq to the indefinite incarceration and torture of prisoners. They would like to see nuclear tests resumed. They cannot understand why US Senators John McCain, John Warner, and Lindsey Graham have held up Pentagon funding by tying it to a bill stipulating humane treatment of prisoners and reasserting the right of accused terrorists to civilized treatment, including counsel and trial.

But McCain, who was a prisoner and tortured in the Vietnam War, knows that civilization itself survives by its values, not military power.

There are those who assert that if atomic bombs explode in the West, retaliatory bombing of Mecca or Iran or Pakistan would be justified. Some felt in 1945 and today that such weapons are simply too horrific to use, even in wartime, even against enemies as fanatical as Nazis and Japanese and Islamic terrorists.

Whatever conclusion you may draw about the use of atom bombs in 1945, one thing seems clear today; not acknowledging others as humans deserving treatment as equal humans is the source from which the desire to use weapons of mass destruction originates. Torture and terror also stem from this source.

Toleration of different lifestyles and beliefs is the only way to stop use of weapons of mass destruction. Tolerance is the core of civilization. Without it, our city would not be here to welcome us back from holiday.

degolyer@hkbu.edu.hk

Michael DeGolyer is a professor of the government and international studies department at Hong Kong Baptist University