Eastern Europe received what could be a healthy dose of fresh air when it was learned this week the Soviet Union may pull its troops out of Hungary, where they have been since the end of World War II.

While an actual withdrawal of Soviet troops has yet to be realized, it appears the Soviets are serious about improving relations, not only with the West, but with the East Bloc.The Soviet move, if it happens, will begin to erase one of the remaining vestiges of Cold War repression, and it will serve current Soviet interests as well.

Those interests include promoting Gorbachev's desire to maintain the general momentum of arms reductions talks with the United States and to increase Western Europe's expectations that deeper cuts in conventional armaments could result.

A Soviet pullout would also encourage communist states to undertake measures that parallel economic and political reforms being sought in the Soviet Union. Those countries will be more willing to take economic and political risks if the shadow of the Red Army is removed.

It would be even better if the pullout of Soviet troops from Hungary were followed by a withdrawal of troops from Czechoslavakia. Unlike Hungary, however, there is no sign the Czech Communist Party leaders are willing to implement reforms.

Even with the removal of Russian forces from Hungary, there would continue to be a considerable troop force disparity in East Europe in favor of the Warsaw Pact. In the region from the Ural Mountains to the Atlantic Ocean, Eastern Bloc nations would have a two-to-one advantage over NATO tanks, artillery, and armored infantry fighting vehicles.

While the withdrawal may be a positive move, optimism should not cloud the fact there are still many stumbling blocks to be worked out before Soviet armies no longer cast a shadow across Eastern Europe.