Megabombs and their megastatistics

Earlier this month the civil defense coordinator of the United States Postal Service, testifying before a House subcommittee, assured the Congress and the nation that radioactive fallout would no more stop the American postman than snow, rain, or gloom of night. In the event of nuclear war, he said, ''those that are left will get their mail,'' ignoring the protest of Rep. Edward Markey (D) of Massachusetts: ''But there will be no addresses, no streets, no blocks, no houses.''

The country seems to be polarizing into doves who believe World War III would terminate civilization with the first strike and hawks who say: What's a little nuclear war if you prepare yourself and manage it properly?

The first part of the summer the headlines went to the nuclear freeze demonstrators. But now the Pentagon has delivered to the National Security Council a plan detailing how the US could win a ''protracted'' nuclear war with the Soviet Union, and there appears to be a more or less orchestrated effort by the hawks to prove that a nuclear war would be war-as-usual.

A member of the advisory board for the Arms Control and Disarmament Agency has gone so far as to argue that the loss of 20 million Americans in a nuclear war would not exceed a limit ''compatible with Western values.''

The innocent bystander is tempted to ask: Exactly which ''Western values?'' And how do ''Western values'' differ from Eastern values, or whatever, when 20 million lives are being tossed around? In fact, since when is the loss of tens of millions of lives ''compatible'' with anybody's ''values,'' strategic as well as moral?

One can understand why the Pentagon, and even the State Department, might worry that the nuclear freeze movement is sending a signal to potential enemies that Americans lack, as the saying goes, the will to resist. But surely it is overreacting to accept the prospect of 1 out of 11 Americans being killed - and then proclaim such a catastrophe ''compatible with Western values.''

The malaise of the megastatistic is that, after the first shock, one develops a quick and easy tolerance for it. Once you learn to roll through all those terminal zeros, like a surfer on an endless wave, a megastatistic becomes just another number in a world that uses numbers almost as carelessly as words.

We have acquired the knack of speaking casually in terms of billions of dollars of debt. Are we now teaching ourselves to speak with equal nonchalance about millions of lives? - 50 times as many as we lost in World War II, two-thirds of our total population at the time of the Civil War!

In its current issue Mother Jones magazine notes that the habit of treating nuclear war as an ordinary event dates back more than 25 years. In an article titled ''Atoms, Strategy and Policy'' a State department officer named Paul Nitze concluded in 1956: ''It is quite possible that in a general nuclear war one side or the other could win decisively.'' The secret, Nitze thought not too suprisingly, was a bigger stockpile: ''The greater our superiority, the greater our chances of seeing to it that nuclear war, if it comes, is fought rationally.''

A ''rational'' war. A war ''compatible with Western values.'' How strangely these quaint descriptions can sound, so soon after another anniversary of Hiroshima!

It is curious. Decent men who would not dream of committing an act of rudeness against an individual can go to their offices and contemplate with at least some equanimity the extermination of tens of millions of human beings as if they were blips on a video-game screen.

If the no-nukes doves can see nothing but the corpses of babies, the war-games hawks, with their ever-escalating scenarios, seem to have abstracted World War III into their computers. The motive for peace should not be raw fear. But there is a cold hysteria as well as a hot hysteria, and we really ought not to wish to go down in history as the calm realists of holocaust whose bottom line read: ''That's not so bad - we can live with that.''