NO MATTER WHETHER Soviet Foreign Minister Eduard Shevardnadze's stunning resignation was a calculated bid to spotlight -- and thus pre-empt -- a possible right-wing takeover or simply the surrender of a disenchanted reformer, it is a bad sign.
The move comes as President Mikhail S. Gorbachev's grip on power is at its most tenuous since he inaugurated a period of unprecedented change.
The West has a vital interest in the success of his reform program. But it also has an interest in what happens when Gorbachev is no longer around, no matter if that period comes sooner or later.
The world must be concerned about the calls for Gorbachev to crack down and about Gorbachev's own bid for more power under a proposed treaty with the country's republics.
Given the progress toward disarmament the Soviet Union and the United States have made under Gorbachev, and given Moscow's constructive role in the Persian Gulf crisis, Washington must hope Gorbachev is able to ride out this latest jolt. With the army and other elements of the security establishment as the only organized blocks of power, his fall could lead either to either a military takeover or the disintegration of the Soviet Union into splinter republics.
Neither a return to the hard-line ways of the Cold War era nor the prospect of dealing with rival independent republics -- some of which might well gain control of the nation's nuclear weapons -- would be in the interests of the West.
But a precedent for concentrating more power in the president's hands could be equally dangerous, depending not only on how far Gorbachev must go to quell the current unrest, but on who eventually succeeds him. Despite the changes that have taken place, the food shortages and popular unrest make it far from certain that reforms have gone too far to be reversed.
That is the very fear that prompted Shevardnadze to announce his resignation with the warning that "dictatorship is coming." If that dramatic gesture helps galvanize opposition to the reactionary element, it may well turn out to be a significant contribution rather than an act of abandoning ship.
Already 22 members of the Congress of People's Deputies have coalesced to fight any move toward dictatorship and urge Gorbachev to resist the hard-liners. They are sensibly urging members representing the dissident republics to return to the current meeting of the congress and use their votes to assure the survival of the democratic process.
But the new group also calls for development of a specific program for which Gorbachev could be granted the powers needed for implementation. They warn against simply giving him unspecified powers.
It is a sensible, middle-of-the-road approach, the kind Gorbachev himself has usually tried to take. His style has served him -- and the world -- well to this point. With the continued help of the West in the form of food and other aid to help avert a popular backlash -- but tied to the continued pursuit of reform -- that approach can still pay off.