Several years ago, I heard President Reagan say approximately this:

"I would like to take the Soviet leaders up in a helicopter over Los Angeles." (Here I thought: Good, he is going to push them out. But, no.) "I would point to all the small houses with swimming pools and I would say, 'Those are the workers' houses!'

Surely Ronald Reagan does not think the hard men of the Kremlin are misguided Lane Kirklands, labor leaders mistaken about how best to raise living standards. But Reagan may illustrate the great, and perhaps fatal, paradox of American politics:

He is thumpingly successful because he is thoroughly American -- moderate, amiable, reasonable and convinced that others are too. That is, he has the constricted political imagination natural in a sheltered, liberal nation to which history has been kind. Hence he is, as the most successful American leaders are most likely to be, especially apt to underestimate the terrible dynamic of the Soviet system. One manifestation of this misunderstanding is the sweet thought that the regime's leaders would be susceptible to the taming example of American freedom and affluence.

I mention this now because The Post reports that recently the president was flying over New Hampshire and said to the governor how much he would like to take Gorbachev to "any house down there" to meet "the working people." What does the president think such a visit would accomplish? Perhaps: the Gorbachev palm slapped to the Gorbachev forehead, and a thunderstruck exclamation, "Marx goofed! I have seen the future, and lots of kitchen appliances, and it and they work. So dismantle the Gulag!"

Is this another "It's all a horrid misunderstanding" theory of the Cold War? Usually the "misunderstanding" is a mutual misassessment of the other's peaceful intentions. In this case, the supposed misunderstanding concerns how best to satisfy the common man.

This theory founders on the fact that the thin slice of Soviet society that has power also has material comforts. The regime is driven by the need to justify the exemption of the privileged few from the dismal life led by the many. The regime derives its legitimacy, such as it is, from the pretense that it is custodian of History's progressive impulse. That is why the Soviet regime is not -- cannot be -- in the live-and-let-live business.

If the leader of this regime were not following in the shuffling footsteps of three cadaverous leaders, he would be seen to have the charisma of suet pudding. Yes, he is "resplendent" in his "gleaming white shirt" (words from the introduction to his self-interview in Time). But he is also a truculent liar: he is truculent when dismissing as "insubstantial" all complaints about Soviet violations of its Helsinki undertakings. He is a liar explaining how tickled Jews are about the privilege of remaining in the Soviet Union.

The "bold, new" arms control proposal is bold in offering something so old. It is traditional Soviet algebra: X equals X plus Y plus Z. The Soviets offer X (50 percent reduction of "strategic" forces); the United States will give X, and will count its intermediate-range forces as strategic, and will kill its attempt to catch up with the Soviet strategic defense initiative. The Soviet side wins not by getting us to accept its equation, but by getting us to talk, exclusively, the arcane, antiseptic algebra of arms control.

It is axiomatic: control the agenda and you control the meeting. Regarding summit meetings, the axiom is: control the presummit conversation and you control the event. And look what is happening. Throughout the 1970s conservatives sensibly criticized the policy of treating arms control as the centerpiece of U.S.-Soviet relations. Today we see a Gresham's law of political discourse. The dry arcana of arms control has driven out talk of all other things, including: Afghanistan, Poland, Angola, Nicaragua, yellow rain, terrorism, arms-control violations, Helsinki violations, etc.

In another way, too, America is paying the price of its arms control obsession. So eager were the Nixon and Carter administrations for agreements, they prenegotiated (in Washington) proposals compatible with the Soviet buildup. Then they settled for agreements that were, essentially, mere snapshots of the rising force levels. But Soviet levels rose faster. Today they are so large and varied that a mutual cut of 50 percent could be tailored that would leave the Soviets with an enhanced strategic advantage.

The lament of correct thinkers within the administration is: the Soviets would never attend a "Sakharov Summit" or an "Afghanistan Summit," but here we go to a "Star Wars Summit." And the (definite article, "the") question already is: what will Reagan give up to make it a "success"? This, too, is a reason why, when I hear people praising summits, I want to take them up in a helicopter and . . .