For a regime that fancies itself the vanguard of revolution, the vessel of history, fountain of progress, destroyer of reaction and consigner of outmoded things to the ash can of history, the Soviet regime is remarkably tradition-bound in one regard. It clings to its animosities.

Some societies define themselves in their admirations, some in their animosities. America defines itself in admiration of Washington, Jefferson, Lincoln. The Soviet regime (Soviet society has no voice) bristles with defining animosities, the most durable of which is for poor old Leon Trotsky.

Not content with having driven him into exile, even into rural Mexico, and having sent thither an assassin to drive an ice axe into his skull, the regime took the trouble to erase him from history books and even from photographs (some of which showed him distressingly close to the sainted Lenin). But now Trotsky is back, for another bashing. A Los Angeles Times headline says: "Trotsky Revived as Villain in Soviet Play." The subhead is: "Discredited Old Bolshevik Portrayed as Double Agent."

Decades ago Trotsky was slung down the memory hole. It was as though he had never existed. That was rude treatment for the creator of the Red Army, which saved the Russian Revolution.

But Trotsky ran into trouble with Stalin. Trouble with Stalin was fatal for millions. For Trotsky it was singularly obliterating. Yet now he has been resurrected so that he may be condemned to death yet again, this time by a play that portrays him as Stalin did -- as an anti-Bolshevik.

The Trotsky-Stalin feud was dressed up in ideological nuances. Trotsky, who had a powerful if warped and narrow mind, said Soviet Russia could not survive isolation, so there must be world revolution, pronto. Stalin, who would have lowered the intellectual tone of the St. Valentine's Day Massacre, argued for "socialism in one country." But the real issue was that the Soviet Union, which spans 10 time zones, was too small for the two of them.

What does the reemergence of Trotsky, if only for another drubbing, mean? It probably is additional evidence of the de-de-Stalinization of the Soviet Union, the rehabilitation of Stalin, the most prolific killer of the most killing century. (An enchanting rumor is that Volgograd, which was Tsaritsyn until 1925 and then was Stalingrad until 1961, may soon be Stalingrad again.)

The anti-Trotsky play certainly is evidence of the amazing continuity of the basic impulses that animate the Soviet regime. Denial of such continuity is an essential component of the mental makeup of Western enthusiasts for the arms control process. They always see the Soviet Union on the verge of "fundamental" chnge.

In totalitarian societies little things, such as the reappearance of Trotsky, mean a lot. So they are not really little. Churchill knew this.

In April 1933, less than two months after Hitler seized power, Churchill warned Parliament of such German "martial and pugnacious manifestations" as "appeals to every form of the fighting spirit, from the reintroduction of dueling in the colleges to the Minister of Education advising the plentiful use of the cane in the elementary schools." Churchill noted these things because he knew what many of today's arms control enthusiasts ignore: There is a link between the internal dynamic and external behavior of a totalitarian society. A system sustained by the Gulag Archipelago is not tamarchment covered by arms control phrases. That is why it was right for Avital Scharansky, the wife of the most famous Jewish prisoner of conscience in the Soviet Union, to be here haunting the proceedings.

Now, return to the Los Angeles Times story about the re-denouncing of Trotsky in accordance with Stalin's old mythology. The story contains this hilarious sentence: "Western observers of cultural trends say that publication of the play may reflect increased official willingness to be more realistic about Soviet history."

Of course. The reappearance of an utterly traditional, utterly tendentious fable of Stalinist history is evidence of -- what else? -- new "realism" and, therefore, is grounds for optimism about U.S.-Soviet relations. So say the usual suspects, those "Western observers of cultural trends."

The moral of this little story about Trotsky is timely, and should be spelled out in neon across Geneva, the host to the world's recurring illusions. The moral of the story is this:

There is a mobile army of "Western observers" whose observations condition the atmosphere that produces things like the arms control process. These observers can be counted on to announce that anything -- absolutely anything -- that happens in the Soviet Union is heartening, the harbinger of "realism" and a reason for hastening to Geneva and expecting "fundamental change."