If Mikhail Gorbachev is so smart, how come he hasn't signed up Michael Deaver as his public relations man in Washington?

Gorbachev needs a super-flack here. He has been pushing a nuclear test ban, and from the way the Reagan administration has reacted, you'd think he was peddling poisoned Tylenol.

The White House angrily calls his test-ban idea "a propaganda ploy." Secretary of State George P. Shultz growls at him for practicing "public diplomacy." The Europeans are too busy signing "Star Wars" contracts to notice; the Democrats are stewing over President Reagan's polls, and the U.S. peace movement is out to lunch.

Deaver, who used to be White House deputy chief of staff, could change all this. He strolls into the White House any time he likes to chat up the president and the first lady.

There would be risks from his point of view. But you don't build up a business worth $18 million (the price he expects soon to sell it for) by being squeamish about the clientele -- he represents the military dictatorship of South Korea, for instance.

Deaver should demand combat pay from the Kremlin after telling the comrades what it's like to do business with the College Young Republicans and other militant cadres. The right wing recently forced Robert K. Gray to drop an account ($20,000 a month) with the Marxist-Leninist government of Angola. Besides picketing Gray's posh Georgetown headquarters, they ginned up contract-cancellation threats from his conservative customers.

Gray caved, which is too bad. He could have blown the righties out of the water with a few swift moves. If he had invited the Marxist-Leninists who run Angola over here, set up a few photo-ops for them with David Rockefeller, the president of Gulf Oil and other Republican Eagles who have had no trouble doing business with Red Angola, the whole thing would have dissolved in giggles.

Gray's rivals at the firm of Black, Manafort, Stone & Kelly who handle Jonas Savimbi, the Maoist leader of the Angolan rebels ($600,000), were highly amused -- until they lost their account with Nigeria ($1 million), which regards Savimbi as a stooge of the South Africans.

If he signs up with Gorbachev, Deaver could lose his billing with the South Koreans ($1 million) but could pick up Albania. The top dollar, say $5 billion, would not be too much to ask. It's certainly less than Gorbachev will have to shell out on weapons if Reagan barges ahead with his arms buildup.

Gorbachev would not quibble in the contract negotiations. A glance at Deaver's portfolio would show him that in Deaver he would be dealing with someone who delivers, who is not beset by ethical/legal hangups.

Just this week, we learned about Deaver's little intervention in behalf of the Rockwell International Corp. ($250,000). Deaver went right to the man who writes the checks, Office of Managment and Budget Director James C. Miller III, to tell him about the B1 bomber, a Rockwell product that has been losing altitude lately to the more expensive Stealth.

Deaver said he didn't break the rules because the White House budget office is "separate" from the White House, and besides, he didn't work on the B1 while he was in the president's employ.

Most people believe the last half of that statement, since Deaver was not an issues man when he was Reagan's deputy chief of staff. His gift was to translate issues into political formulations and picture possibilities.

For instance, he is credited with turning the president around on acid rain. Reagan for years fought off evidence that U.S. smokestacks were turning New England and Canadian lakes into sewers. But Deaver, who represents Canada (at a bargain rate of $100,000), slipped in and explained that Canadian Prime Minister Brian Mulroney, a brother conservative and an imminent White House guest, would sulk for the cameras if he got no action on acid rain -- and probably not be reelected.

Reagan saw the light.

Deaver could repeat the miracle on arms control, which Reagan just can't see for his arms buildup. But Deaver could work the "cemetery" argument, which rests on the unproven thesis that Reagan, or possibly his wife, is concerned about the inscription on his tomb. Deaver, master visualist, could show gravestone mockups, one with "Peacemaker" and the other with "Peacekeeper" -- the name for the MX missile dreamed up when the missile was in trouble. He could point out how much better the first would photograph.

Let's hope that Gorbachev gets wise about how things get done in Washington and looks up Deaver. Money talks; access is all. It's about our only hope for world peace.