BUDAPEST -- For U.S. hawks, Mikhail Gorbachev has finally torn off his smiling mask. He emerges as just another rotten Russian, trying to smother space-based defense in its crib and subjecting a weakened American leader to last-minute haggling. For doves, on the other hand, Mr. Glasnost appears to be retreating before pressure in the Politburo. He needs understanding from our side.

Gorbachev's sudden scuttling of an immediate Euromissile treaty and a Washington summit this month is provoking a heavy dose of such "either/or," black-and-white analysis. Consider for a moment a European, grayish hypothesis: As is usually the case with decision-makers, even communist ones, Gorbachev is responding to multiple pressures by buying himself a little time and seeking a little extra advantage.

That would mean that he is almost certain to be back, and soon, to wrap up a deal that he clearly wants. He will also continue to poke and pry at SDI in hopes of landing the larger deal that he ultimately needs.

First, however, he has to deliver a State of the Kremlin speech to a restive Central Committee on Nov. 2 and then preside over the celebration of the 70th anniversary of the Bolshevik Revolution five days later. That may be easier without the missile treaty in final form hanging around his neck.

The other gain from the delay he has engineered on the Euromissile accord is that he can pocket the most recent U.S. concessions made in Moscow -- primarily the capturing of Pershing IA warheads in a treaty protocol, as the Soviets have been demanding -- and come back for more while talks go on.

Gorbachev can at this point have no realistic hope of obtaining limits on SDI by holding up the Euromissile deal. His real target in seeking the delay must lie elsewhere. My sense is that it is in the process that the experts call "compensation," the deployment or creation of new weapons systems to cover the Soviet targets now under the threat of the Pershing II and ground-launched cruise missiles the treaty will eliminate.

Speaking at an East-West media conference here in Budapest last weekend, Vladimir Lomeiko, a Soviet foreign policy spokesman, gave what I took as a clear hint of this new emphasis in the Soviet negotiating position. Asked about the Moscow deadlock, Lomeiko said Gorbachev strongly opposes "attempts in NATO to introduce new {air-launched} cruise rockets as a substitute" for the ground-based systems.

Moreover, as part of his response to Secretary of State George P. Shultz in Moscow, Gorbachev made the first specific Soviet proposals for limits on air-launched cruise missiles (ALCMs), which do form a significant part of the NATO compensation package under discussion in Brussels and other allied capitals.

Limits on ALCMs (phonetically, Al-kims) are handled in the Strategic Arms Reduction Talks, not in the Euromissile basket. But by seeking commitments from the United States now, Gorbachev clearly hopes to tie such limits to the Euromissile package the White House wants so much.

East Europeans at the Alerdinck media conference or on its edges spent little time analyzing such hardware questions but focused instead on something far more urgent to them: Gorbachev's grip on power after three months of unsettling and unsatisfactorily explained developments, such as his 56-day disappearance from view while "on vacation" and attacks on glasnost by other Politburo members while he was away.

These are telltale signs of divergences within the Soviet leadership, although it is impossible for outsiders to tell how sharp these splits are. For some of the Europeans here who live in the grasp of the Soviet bear, Gorbachev's success in dumping Gaidar Aliyev from the Politburo two days before Shultz arrived for his cold shower bore the marks of a tradeoff with Kremlin partners who may have wanted to slow down the rush to a summit.

In these circumstances, Gorbachev's Nov. 2 speech takes on an importance far beyond its role as an equivalent of the State of the Union address of an American president. East Europeans will scrutinize it closely for signs of a struggle over Gorbachev's domestic programs of economic renewal and political change, and the reduction of international tensions that he says must underpin those programs. It is small wonder that the Soviet leader may have preferred to finesse the Euromissile accord until after the Nov. 2 hand has been played out.