In the frenzy of demonizing Saddam Hussein, it is easy to forget that the United States has got nerve gas too. The Iraqi stuff is castor oil compared with our concoctions. But we keep it stashed away. The United States has a habit of making exotic weapons and developing new technologies of destruction that we later decide are too awful to be used.

The cynic might wonder why the rules of war permit killing a person with metal shrapnel but not with gas. The answer, in simplest terms, is that military action is supposed to be discriminate and proportional. You have to target the enemy selectively, and then inflict no greater harm than is needed to fulfill the military objective.

Gas seems like overkill.

Yet since the war began, U.S. officials have declined to rule out the retaliatory use of these weapons. The Washington Post has reported that, privately, Pentagon officials say they've decided against using them. Their public face is more inscrutable, probably an attempt to maintain a deterrent. Secretary of Defense Richard Cheney was asked Wednesday if the United States would respond "in kind" to chemical attacks by Iraq. He said, "I would simply reiterate what we have said previously, which is that the United States has a broad spectrum of capabilities available, that the president would make the decision about how we might respond to an unconventional attack by Saddam Hussein against U.S. or allied forces, and I wouldn't want to speculate further."

Military officials have told The Post that none of the United States' chemical weapons are currently in the Persian Gulf. That doesn't mean much if Iraq uses such weapons, though. "The chemical stockpiles are anywhere from 12 to 14 hours away," says Anthony Cordesman, professor of national security studies at Georgetown University. "If they're not {actually in the gulf}, so what?" He adds, "I think the United States would do the utmost never to use such weapons, but one thing we have to take into account is that we are dealing with a level of terror in escalation."

Chemical warfare was inaugurated on April 22, 1915, when the Germans released a hideous yellow-green cloud of mustard gas against French troops in the Battle of Ypres. Within hours there were 5,000 dead and 10,000 injured. By war's end 91,000 soldiers had been gassed to death and 1.2 million more injured.

The Geneva Protocol of 1925 banned the first use of chemical or biological weapons. Use of such weapons since has been rare. Scientists, though, have continued to cook up ever more Mephistophelean mixtures. Nerve gas production lapsed in 1969 when President Nixon said use of such weapons is "repugnant to the conscience of mankind," but was revived by President Reagan in 1987. Three times, then-Vice President Bush, sitting as president of the Senate, cast tie-breaking votes to allow chemical weapons production to go forward.

Production of new weapons has since ceased, in part because chemical companies stopped supplying the military with the raw materials. Much of the U.S. stockpile is scheduled to be destroyed by 1997. By then, we may wonder why so many millions of dollars were spent on killing techniques that couldn't be used conscionably.

On the Ellipse, shouts of anti-war protest blew out from megaphones and scudded along in Saturday's cold wind. Protesters stopped here and there -- the Lincoln Memorial, the Reflecting Pool, outside the Corcoran -- and laid down their signs. They took a moment for themselves.

At the Air and Space Museum, protesters strolled under war planes, around missiles. Overhead, satellites like those bringing us news from the Persian Gulf dangled like ornaments, shining kites, new toys.

"DOWN WITH KING GEORGE," said one sign relaxing on the grass. "SEND DAN QUAYLE" and "SEND NEIL BUSH," sighed other signs. A wry little self-conscious sign said: "ANOTHER PETIT BOURGEOIS AGAINST THE WAR."

War is never funny, of course, but war protest signs are often darkly funny -- bitter, imaginative, silly, nasty. They are meant to shock. Of all the thousands carried here Saturday, the slogans conjured up, apparently, by women seemed to have the most new things to say:





There was also a contingent of Wisconsin protesters making themselves known: "CHEDDARHEADS FOR PEACE."

Sen. Alfonse D'Amato (R-N.Y.), visiting Israel, was given a fragment of a downed Scud missile. Will these replace those chunks of the Berlin Wall?