MOSCOW, NOV. 21 -- Mikhail Gorbachev's first domestic political crisis has forced the Kremlin leader off the front line of a drive for reform, according to western and Soviet analysts here, and exposed divisions within the Communist Party over his policies of openness and economic restructuring.

By leading the dramatic ouster from the Kremlin leadership of Moscow party chief Boris Yeltsin, an outspoken proponent of radical reforms, Gorbachev sacrificed the more radical wing of the reform movement, relinquished his own role in that wing and aligned himself instead with members who favor a moderate pace of reform, analysts said.

According to some western diplomats here, Gorbachev's decision to sacrifice Yeltsin shows political acumen and the will to avoid the fate of Nikita Khrushchev, the reform-minded Soviet leader who was ousted in 1964 after alienating some party officials.

"Gorbachev," a diplomat said, "has decided to survive."

The Kremlin leader's move toward the center, following the unusual display of a rift within the Soviet leadership over the reforms, is widely viewed here as part of a concerted personal effort to forge unity within the party.

Gorbachev's apparent objective is to gird the party for a major conference, scheduled for next June and billed as the final step in consolidating the Kremlin leadership behind the reforms. One possibility is for a midterm election of members of the Central Committee, usually elected for five-year terms. According to some party officials, Gorbachev would like to replace up to 100 of the 300-member body.

Still, Soviet officials and western diplomats are divided over the long-term effect Gorbachev's shift will have on his reforms, or even short-term initiatives such as his planned trip to Washington next month.

A big unknown, for example, is whether Gorbachev's move to the center is tactical, designed to consolidate support for further reforms, or a permanent shift in the face of mounting conservative influence in the party.

The most remarkable aspect of the Yeltsin affair, in which he was fired as the Moscow party chief last week and appointed this week as a senior construction official, is the rare exposure it gave to intraparty differences over the reforms.

By Gorbachev's own account in a speech at a Moscow party meeting on Nov. 11, Yeltsin, a nonvoting member of the Politburo, was rebuked at least twice by the ruling body. According to reports of Yeltsin's Oct. 21 speech before the Central Committee, he accused other members of the Soviet leadership of thwarting his attempts to implement the reforms.

Repairing the resulting rifts in the leadership, apparently one of the most wrenching political maneuvers of Gorbachev's career, has already diminished his bold image, in the view of Moscow-based observers. In the past two months, they have invariably found Gorbachev confusing and indecisive rather than thoughtful and imaginative.

According to one report of Gorbachev's Oct. 23 meeting with Secretary of State George P. Shultz, for instance, the Soviet leader seemed "a bit under pressure." A western diplomat said, "This is not the Gorbachev of grand gestures and sweeping proposals. This is a changed Gorbachev." Tracing the timing of Gorbachev's shift to a more moderate stance on his reforms, Soviet officials and westerners in Moscow focus on the 52-day period in August and September when Gorbachev disappeared from public view.

Emerging from last June's Central Committee plenum, the Soviet leader appeared to have a majority in that powerful body and the ruling Politburo squarely behind his programs of perestroika, meaning economic reform, glasnost, or more openness, and democratization.

After his return in late September the Central Committee was suddenly summoned for another closed-door meeting. Its results were not published. Two days later, on Oct. 23, Gorbachev held the meeting with Shultz in which he refused to set dates for the U.S.-Soviet summit. On Nov. 2, he gave a major address on the occasion of the 70th anniversary of the Soviet Union that was more cautious, particularly in his references to the Stalin era, than had been expected.

A week afterward, Gorbachev called for Yeltsin's ouster as Moscow party chief.

Some western diplomats in Moscow have speculated that, in Gorbachev's absence this summer, a group of Kremlin conservatives organized a majority of the Soviet leadership behind a more conservative interpretation of Gorbachev's reforms. According to this viewpoint, members of the Soviet leadership, united in their general support of perestroika, democratization and glasnost, are nonetheless miles apart in their interpretations of how and at what pace the policies should be applied.

"The differences within the leadership," Soviet historian Roy Medvedev said in a recent interview, "are becoming harder and harder to conceal."

While the Soviet leader was absent, for instance, party ideologist Yegor Ligachev and KGB Director Victor Chebrikov, both members of the Politburo, publicly criticized some of the more liberal manifestations of glasnost, such as street demonstrations. By late September, when Gorbachev returned to Moscow, street demonstrations were banned in most parts of the city's center.

As a result of his shift to the center, Gorbachev is left with diminished support among proponents of his reforms, who were alienated by his treatment of Yeltsin. The Soviet leader presided over the Nov. 11 Moscow party meeting where Yeltsin was removed and publicly criticized Yeltsin, widely regarded as the key proponent of his reforms in the Soviet leadership. "It's obvious that when the captain of the team gets rid of one of the players," said Gleb Pavlovsky, a journalist and member of a Moscow-based independent political discussion group, "it's going to demoralize the team."

Besides the crackdown against street demonstrations, Gorbachev's shift to the center has brought few noticeable changes in policies or their application.

Despite Yeltsin's appointment to a new post and a Central Committee speech by Gorbachev late last week to rally proponents of perestroika, Soviet supporters of Gorbachev's reforms are left shaken. Some of the outspoken official proponents of glasnost, usually quite eager to meet with western reporters, have withdrawn in the wake of Yeltsin's ouster, declining to be interviewed for this article. The editor of a liberal magazine, who asked not to be identified, said, "No one knows quite where this leaves us."

The Yeltsin affair has apparently strengthened the foothold of party conservatives, who interpret the policies of glasnost narrowly, and favor a more moderate pace of introducing economic restructuring.

Even if Gorbachev's move is a tactical one, the stagnating effect on domestic policy decisions is likely to put added pressure on him to achieve successes in foreign policy, analysts here said.

The consensus among them, for instance, is that pressure is probably stronger on the Soviet leader to forge a deal with President Reagan beyond the arms control treaty to be signed in Washington next month, something that is viewed here as only a modest return for Gorbachev's high-profile, two-year-long disarmament campaign.

But Gorbachev's search for a broader base for his reforms takes some of the pressure off the need for immediate results, Soviet and western officials here have said, and puts a new accent on the long-term objectives of the reforms.

Correspondent Celestine Bohlen contributed to this report.