One of the most impressive changes that swept the Soviet Union in the 1980s was "glasnost," Mikhail Gorbachev's term for unprecedented freedom of expression, including freedom of the press in that former tightly controlled society. However, that liberty is now in danger and may not survive.

As the military crackdown against the independence-minded Baltic states drew harsh criticism in some publications, Gorbachev was stung by the reports. He asked the Parliament this week to take control of the Soviet press. That raises ominous echoes of previous brutal Soviet regimes.At first, opponents shouted down the idea, declaring that a relatively free press is the one great achievement since 1985. Gorbachev retreated from his plan to suspend the press laws for one month.

But as he has done on other occasions, Gorbachev refused to take "no" for a final answer and offered the same idea in another guise, namely that the lawmakers would take unspecified steps to "ensure objectivity." This time, deputies, as they also have in the past, accepted the modified second attempt.

The phrase "ensure objectivity" could mean anything, but the power to control the briefly free press is clearly being taken out of the hands of editors and put back in the hands of political leaders. Objectivity is sure to be translated into less honest coverage of events and less criticism of government actions.

Despots have always made control of the media their first objective. As Soviet tanks rolled into Lithuania, the first target was that small country's broadcast center.

Other independent Soviet broadcasters already have had their operations interrupted or seen news programs replaced with Kremlin propa-ganda.

The move against the Soviet media, like the occupation of Lithuiania's broadcast facilities, may be merely the first target in a broader action to crush nascent independence and freedom in the economically and politically shaky Soviet Union.

For as TV newsman Walter Cronkite once aptly put it: "Freedom of the press . . . is not just important to democracy, it is democracy."