All of you out there who believe the Soviet Union has a free press, raise your hands. Just as I thought. You know more than enough about the Soviet system not to have to be told by the White House director of communications, Patrick Buchanan, that a "commentator" for Radio Moscow is a paid propagandist.

Now: Can we assume that when a clearly identified Soviet stooge comes on your TV screen even with a slick American accent (the sly devils), as happened the other night after the president's televised speech on national defense and the Democratic Party response, that your head was not turned against Ronald Reagan or the American way of life? That's what I figured.

But that's not the way minds work at the Reagan/Rambo White House. A phone call would have cleared things up. ABC producers knew they had goofed. They were ready to apologize for allowing "commentator" Vladmir Posner to rant on for nearly seven minutes at the end of what was supposed to be a Republican-Democratic "debate" in a domestic format.

What we got, instead, was a White House tantrum with the president telling congressional leaders he didn't know "why the hell the media is so willing to lend support to the Soviets" and Buchanan sending a steamy public letter to ABC's president for news, Roone Arledge. Buchanan was astonished that a commie stooge was given equal billing with the president of the United States -- as if that's what ABC had intended.

Thus did a relatively trivial incident reveal vivid evidence of administration nerves rubbed raw by budgetary constraints and the consequent unwillingness of Republicans as well as Democrats (not to mention the "media") to see the communist menace exactly the way the administration would have them see it. As happens in cases of extreme frustration, the result is intensified ideological frenzy: an acute onset of what might be called right-wing fright.

By that I mean a collapse of confidence in the same values that the administration supposedly seeks to safeguard by building our defenses and backing "freedom fighters" around the world. The flap over ABC's judgmental lapse makes another, larger point about the administration's confidence in the intelligence and tough- mindedness of the American people.

The irony is that Reagan is the first to trumpet the triumph of American values over communist values, and never more vigorously than when he is talking about freedom of expression. The Soviet system is too weak to allow American access to its people, he says. Fleeting American access was supposed to be one of the useful breakthroughs at November's summit. By his outrage at ABC, did the president mean to imply that the American system can't handle unobstructed Soviet access to the U.S. public?

Buchanan was more explicit, though no less defensive. "The debate over what America requires -- to defend herself, her allies and friends from the awesome military power of the Soviet Union -- is a debate for Americans to conduct," Buchanan told Arledge. "Soviet propagandists have no legitimate role in that discussion."

Nonsense. To fill out dead time in the full hour set aside for the president's speech, ABC cast around for instant commentary and allowed itself to get locked into a Soviet talking head. Bad show. But to generalize from this particular case of malpractice the way that Buchanan does is bad public policy.

The American debate over our national security needs is obviously ours to "conduct." But final decisions have to turn on estimates of the threat -- on Soviet intentions and designs. Reagan had plenty to say about that in his TV talk, as he usually does. The Soviets usually have plenty to say in reply. If Buchanan is saying anything, he is laying it down, as a general rule and as a matter of principle, that the American public ought not even to hear the Soviet reply because it is, God help us, communist propaganda.

That bespeaks weakness, by selling short not only democracy but the common sense of the American people.