A plane flies over a city, and drops a could of plague on the target, wiping it out. It is not the instantaneous mass murder of the mushroom cloud -- it is the slow mass murder of a contagious, incurable disease.

This is chemical-biological warfare, the newest thing in military destruction. The United States is already using it against crops in Vietnam, and is conducting research in the possibility of using it against people.

But a group of American scientists--led by two Harvard professors--is trying to convince President Johnson to abandon the project. Matthew S. Meselson, professor of Biology, and Dr. John T. Edsall, professor of Biological Chemistry, have collected the signatures of over 5000 scientists in support of a letter to Johnson asking him to stop using these weapons in Vietnam, and to "categorically declare the intention of the U.S. to refrain from initiating the use" of them in the future.

At least two Nobel Prize winners are among the signers of the letter, which will probably be sent to the White House in January. All of the signatories have Ph.D.'s or M.D.'s, and over 100 are members of the National Academy of Sciences. It is perhaps the most impressive collective expression of scientists' feelings since physicists lobbied in 1946 to keep control of atomic energy out of the hands of the military.

Super-Insecticide

Chemical and biological weapons don't have to be as dangerous as nuclear armaments, but they can be. A chemical weapon works like an insecticide, except that chemicals may range from only temporarily debilitating to lethal. Biological weaponry works like any disease. In addition to ranging from non-lethal to lethal, a biological weapon can also be non-contagious or contagious. A contagious weapon could even kill people who were not in the original target zone, since the germs could spread to other areas.

After listening to Meselson inveigh against biological warfare, one wonders how anyone anywhere could be in favor of it. Meselson says it is militarily inconvenient, socially disastrous, and no more humane than any other form of war.

For the military, chemical-biological warfare (CB warfare, for short) is too unpredictable. Military strategists cannot measure the exact range a virus will cover, the way they can for a fusion blast. Resistance to the disease would be unknown, and would vary with the victims. The problems of delivering the dose, which would have to be in the form of an aerosol cloud, are technically difficult, Meselson suggests. "Even if it could be improved in the remote future," he says, military control "would suffer along the way."

Meselson admits that CB weaponry is less unpredictable as a strategic weapon. But if we are interested in larger areas, we already have the Bomb.

Although CB weapons work very well against crops, it is easy for human beings to protect themselves by wearing gas masks or entering shelters -- provided they are warned. Only in a surprise attack, then, are the weapons effective. "It puts an enormous premium on the low blow," Meselson says.

The unpredictable, uncontrollable nature of this new style of war has more than just military import. "One step toward controlling war in society," Meselson suggests optimistically, "is to move towards weapons we can control."

Nuclear weapons are reasonably controllable. At least, it would take some time and bureaucratic shuffling about before a great nation could decide to drop one. And nuclear weapons will always be under the thumb of massive, relatively rational, political units because it is too expensive for an individual to make one in his workshop.

There are no such guarantees for CB arms, Meselson maintains. Although they are not cheap now, they will be once the pioneering stage is completed. The result, he suggests, could be disastrous. "Today, a madman in America might climb to the top of a tower for a shooting spree, or put a bomb in an airplane. But if CB weaponry were conventional, maniacs would constitute an enormous threat. An insane man could wipe out New York City."

It would seem possible, of course, for the United States to develop a formula for inexpensive CB weapons without letting the secret out to the public. But once it is known that such a formula exists, people are more likely to have the initiative to duplicate it. Meselson does not carry his argument this far -- he simply implies that if we must have mass annihilators, expensive ones are less undesirable than cheap ones.

More Humane?