The way he is acting, you'd think that President Reagan were fighting charges that he is "soft on communism." His red-baiting in recent weeks has reached a point where it is reasonable to ask how he can bear to go to Geneva and shake hands with Mikhail Gorbachev.

A day after announcing that the United States will test an antisatellite weapon in space, his administration accused the Soviets of conducting a kind of chemical warfare against Americans in Moscow. The Soviets have been spraying Americans' steering wheels and doorknobs with a "tracking substance," initially described as a potentially cancer-causing "mutagen" but then termed something less lethal. A team of doctors has been melodramatically dispatched to Moscow to check the victims.

It is also reasonable to ask if Reagan is trying to goad Gorbachev into calling off the summit. If not, he is serving notice that Gorbachev, who has come on as a matinee idol in the European press, will get no quarter in Geneva.

If Gorbachev thinks he will face a defensive and ailing old man, he is wrong. He's going up against Rambo. Reagan will be a furious warrior prepared to smite the Red with charges about cheating on arms treaties and powdering innocent Americans with spy-dust. And there will be no retreat on "Star Wars." The antisatellite test speaks volumes to the contrary.

Sen. John P. Kerry (D-Mass.), who proposed a ban on ASAT testing, says he finds the administration's announcement "unbelievable" -- and revealing. "It is his notion of how to approach the talks, his notion of bargaining. He is trying to set up the summit in his terms, so that when it doesn't produce anything, it can be blamed on the Soviets, who won't talk because they are ahead of us."

Kerry contends that Reagan's claim that he has met the conditions on ASAT testing established by Congress is contradicted by Reagan's statement, which says we are "studying" the limits on antisatellite weapons: Congress required "good-faith negotiations." Reagan baldly claims that the "U.S. must develop its own ASAT capability in order to deter Soviet threats to U.S. and allied space systems."

"The facts are," says Kerry, "that the Soviets have a very rudimentary system. They've had it for 15 years, they declared a moratorium on testing two years ago. And we're going to test ours two months before the summit. Congress said he could test only if he is negotiating on ASATs. They aren't on the table in Geneva. But he certifies while Congress is in recess. It all shows where he's coming from on arms control."

The announcement of the antisatellite testing follows closely the Reagan rejection of a Soviet offer, made on the eve of the anniversary of Hiroshima, of a comprehensive test ban. It was dismissed as a crass "propaganda ploy" and cuttingly countered with an invitation to the Soviets to come watch our tests.

The message: Don't get smart with me, Gorbachev.

Last Monday, out of the blue, national security affairs adviser Robert C. McFarlane made a crushing speech warning the Soviets that they could expect nothing from us unless they change their ways. It was an echo of an early first-term utterance by Richard Pipes, who told the Soviets that they must change or expect war. He caused a furor; McFarlane's gratuitous attack was explained as a preemptive strike in the anticipated pre-summit Soviet "propaganda offensive."

The clenched fist is, apparently, to be the logo of the second Reagan term. A domestic war council produces threats of confrontations for Congress; the moral crisis in South Africa is stubbornly viewed as a battle in the Cold War; press disclosures that a member of the National Security Council is running the contra operation in Nicaragua is countered with a White House demand that the commandante's name be withheld.

Gorbachev is not to think for a minute that Reagan is a lame duck. The president can show his contempt for Congress, as in the high-handed ASAT certification notice; he can turn his back on public opinion, and he can get away with it all.

Gorbachev has to be pummeled so that he goes into the summit wary and off his game. The president will be brandishing nukes and blasting away about sinster spy-dust sprayed on innocent Americans in the capital of the Evil Empire.

Reagan has lowered expectations to a level that if the summit's outcome is an exchange of ballet dancers and a chess player or two, everyone will be relieved enough to call it a triumph.

Maybe it would be better if, in his present frame of mind, he didn't go at all.