MOSCOW, DEC. 20 -- Eduard Shevardnadze's resignation means much more to Mikhail Gorbachev than simply the loss of a foreign minister who had won the confidence of the West. It also represents the dismantling of the team he put together in 1985 to lead the Soviet Union into the modern world.

When he walked to the Kremlin podium this afternoon to try to defuse the effect of Shevardnadze's bombshell, the Soviet president seemed a lonely man. He spoke as if he had just lost a political soulmate, a person in whom he was able to confide back in the days when it was dangerous for an aspiring leader to speak his innermost thoughts out loud.

Gorbachev and Shevardnadze worked together in the 1970s in the southern Transcaucasus region. Gorbachev was party secretary in the agricultural province of Stavropol which borders on Georgia, Shevardnadze's fiefdom. They frequently joined each other on vacation and seem to have spent hours discussing the plight of the world's second superpower. In a recent speech, Gorbachev recalled that it was Shevardnadze who first told him that "everything was rotten" in the Soviet Union and that "it is impossible to go on living like this."

"It's strange," said Gorbachev today, musing about the way in which he and his friend have ended up taking different paths. "It was 10 years ago that he embarked on this hard road of struggle for a bright new future. He wasn't afraid then. And now, after all the trials we have gone through together . . . . "

One by one, the politicians who launched the Soviet Union on its great experiment have gone their separate ways. Boris Yeltsin joined the opposition, arguing that Gorbachev was not going fast enough. Yegor Ligachev concluded that Gorbachev's perestroika reforms had gotten out of hand and were leading inexorably to the destruction of socialism. Alexander Yakovlev, the brains behind glasnost, or openness, has effectively retired from active politics. Prime Minister Nikolai Ryzhkov is on his way out, the victim of the government's rock-bottom popularity. And now it is Shevardnadze's turn.

With hindsight, it is not surprising that this has happened. In the beginning, it was easy enough for politicians of many different persuasions to agree with Gorbachev and Shevardnadze that things could not go on as they were. As perestroika has spawned new economic and ethnic strains, raising questions about the future of the Soviet Union, it is not surprising that politicians should have radically different ideas about how to proceed.

In the Kremlin's glass-and-marble Palace of Congresses today, legislators were abuzz with speculation over whether Shevardnadze's resignation would help or harm Gorbachev. Some accused him of abandoning the president at his time of greatest need. Others argued that he had selflessly sacrificed himself to draw worldwide attention to the drift to dictatorship.

"This action is a gift to Gorbachev's enemies," insisted Ivan Laptev, the chairman of one of two parliamentary chambers. "That should be as clear as light. If one of Gorbachev's allies resigns, that means that his enemies become that much stronger, even if Shevardnadze does not join the opposite camp."

"I think this is a serious warning to world public opinion and our own people about the possibility of a dictatorship," said Oleg Bogomolov, an influential academic who heads Moscow's institute for the study of socialism. "Shevardnadze's resignation is a courageous and well-thought-out action that he has been pondering for some time."

The contrast between the mood at this week's Congress of People's Deputies and the first Congress that convened in May 1989 is startling. Back then, it was the radicals who were taking initiatives, forming a faction known as the Inter-Regional Group to put pressure on Gorbachev to step up the pace of reform. Today, they seem disheartened and fragmented, while the conservatives rush around making speeches and proposing resolutions.

"We are witnessing the rise of a vengeful and merciless conservative wave," said Yakovlev, Shevardnadze's closest ally in the old leadership. "I'm extremely worried by the indifference and fatigue of the democratic forces."

In the past, Gorbachev has sought to preserve a balance between left and right. If he sticks to his old political instincts, he is likely to react to the loss of Shevardnadze by making some move that will reassure the radicals. But many liberal deputies fear that he has taken so many steps in the direction of the conservatives that he risks becoming either their hostage or their next victim.

"Shevardnadze's resignation is a consequence of massive pressure exerted by the right-wing forces," said Nikolai Tutov, a radical army officer. "First it was {liberal interior minister Vadim} Bakatin and now Shevardnadze. Who will be next? I don't rule out that it will be Gorbachev himself."