Beset by a collapsing economy and dissident states threatening to pull out of the Soviet Union, President Mikhail Gorbachev appears to have begun sharing power with the military and perhaps some old hard-line communists. Whether this sharing was voluntary or not is unclear, but it is evident that the heady sense of democracy and openness in the country is fading.

In recent months, much of the Soviet news media has been muzzled, more authority has been given to the dreaded secret police or KGB, the military has launched a bloody crackdown in the independence-minded Baltic states, and now troops are being used to patrol streets in most major cities throughout the country - ostensibly an anti-crime measure but obviously extending army control.And the army is being blamed for the recent Soviet retreat from some of the earlier, more resonable positions it had taken on arms control.

The return of old-style despotic rule has two possible explanations, both related.

One is that economic and political turmoil in the Soviet Union is so critical that the survival of the nation is at stake and a crackdown is considered necessary to maintain order. A second reason may be that hard-liners have used unsettled conditions as a pretext to seize power - or at least a share of power. The truth might even be a mixture of both possibilities.

One thing is certain: The Soviet economy is in shambles, perhaps far worse than the Western world appreciates. The Soviet Communist Party Central Committee met last week to discuss ways of trying to salvage the economy and avert total political chaos at the same time.

The outcome reinforced the sense of a new hard-line approach to problems and also underscored Gorbachev's shaky position.

The committee condemned restless Soviet republics for "lawlessness." It also raised the possibility that Gorbachev might be removed as head of the party, thus reducing his power even as he continues as Soviet president.

Gorbachev is caught in a difficult position. If he doesn't use the army as glue to contain the Baltics and other republics seeking independence, the country might collapse into a dozen fractions. If he does use the army, he alienates the West, which already is threatening to withhold desperatelyneeded aid. In any case, Kremlin observers say he is not completely in control of the government and cannot act alone.

At this point, preserving the union seems to be the highest priority for the Kremlin, taking precedence over political reforms, foreign policy or even the economy. Halting the disintegration won't be easy. Having unleashed freedom and ethnic desires for independence, neither Gorbachev nor the army may be able to put it back in the box.

In the minds of many Soviet citizens, Gorbachev's survival and his reforms are not the most important objectives. The Soviet leader may be popular abroad - at least he was popular before the Baltic mess - but he is disliked by many at home. A ruined economy and no food in the stores are being blamed on Gorbachev, although neither is his fault.

Communism ruined the Soviet Union, but efforts to undo the damage and move to a free-market economy are bound to bring some chaos for a time.

The danger is that instead of pressing ahead, the Soviets may retreat into the old order that - despite all its miseries - at least is more familiar than the risks and uncertainties that sometimes go with freedom and free enterprise. Yet turning back the clock would be a disaster. The old order is at the roots of the present mess.

The ultimate hope is that Gorbachev's remarkable reforms can somehow survive and grow, with or without Gorbachev himself.