FROM THE BEGINNING, the politics of the dance-and-defection struggle must have seemed baffling to many. For to great numbers of people, ballet probably seems about as far from politics as you can get. It is fantasy: women whose bodies look so fragile and delicate that they hardly resemble the housings the rest of us occupy, and men who leap rather than walk. It is ethereal, timeless and utterly divorced from the stuff of everyday life. But not in the Soviet Union. There the ballet, like every other form of human endeavor, is suffused with politics. And so the defection last week of Aleksandr Godunov meant more than just another great gain for Western balletomanes.

The Bolshoi Ballet, of which Mr. Godunov was a member, now is Russia's leading troupe. But this was not always so. Once it was Leningrad's Kirov Ballet that danced before the czars and was the only company great stars wished to belong to. With the revolution, the center of Russian life shifted to Moscow, and Bolshoi and Kirov exchanged rank and privilege.

Just as the Kirov had reflected the elegance and French influence preferred by the czars, so the Bolshoi aimed to please its new patrons, the commissars. Where the Kirov had meant the pure classical line, precision and distilled emotion, the Bolshoi is coarser, more athletic, emotive and grandiose. Where the Kirov had tolerated a certain artistic freedom of expression, the Bolshoi, in the shadow of the Kremlin, has been much more closely supervised and is strictly party line. Sharp-eyed connoisseurs can spot the party members disturbing the harmony of the chorus.Even among solo dancers, there are Bolshoi performers who appear to have won their place more for political than artistic merit. The curtain calls are rigidly hierarchical and are subjected by the audience to the same minute analysis that foreigners give to where Politburo members stand on important occasions.

When Mr. Godunov walked off the street into the New York office of the Immigration and Naturalization Service and asked for asylum, he became the first Bolshoi dancer ever to defect. The other Russian stars who have recently defected and thereby transformed American ballet -- Nureyev, Baryshnikov and Makarova -- have all come from the Kirov. Their departures meant fewer foreign tours for that company, closer official scrutiny and devastating morale problems for the younger dancers. Until last week, none of this had touched the Bolshoi.

It is easy to underestimate how difficult a step defection is for a Russian artist. It is, after all, a permanent severing from home, family and culture, for defection is a crime not easily forgiven by the party watchdogs. For obvious reasons, defectors are treated harshly, and the bureaucracy has a very long memory. Mr. Nureyev, who has been rigidly apolitical since he defected 18 years ago, has been trying without success to see his mother for almost that long. Even requests for a short meeting in a neutral European city go unanswered. Though the top stars may win enormous fame and wealth in the West while their dancing years last, they are also leaving behind positions, especially if they come from the Bolshoi, of great privilege and material comfort -- again, by Soviet standards.

The line between art and politics in the Soviet Union is hazy, and we still do not know what reasons propelled Mr. Godunov to take this personally momentous step. But without putting words in his mouth, it would not be making too much of this defection to note once again how powerful is the pull of freedom.