MOSCOW, OCT. 24 -- Mikhail Gorbachev's last-minute refusal to set a date for a summit meeting with President Reagan in Washington was a last-ditch tactical move by the Soviet leader to pressure Reagan into limiting his controversial plan to develop the "Star Wars" antimissile space defense system. But it was also a tactic that could diminish the Kremlin leader's prestige and overall influence on the U.S.-Soviet arms control process.

That is the view of western diplomats in the Soviet capital, who regard the Gorbachev move, made at the end of two days of senior-level U.S.-Soviet talks here, as the Kremlin leader's first serious foreign policy miscalculation during 2 1/2 years in power.

Although Gorbachev told U.S. Secretary of State George P. Shultz that he still would be prepared to hold a summit meeting this year -- as had been agreed upon last month when Soviet Foreign Minister Eduard Shevardnadze visited Washington -- he apparently miscalculated the disappointment and criticism that his sudden change of the terms of the summit would arouse in the West, some analysts here said.

At a time when Americans and West Europeans are reexamining the extent to which they can trust the communist-ruled countries of the Soviet Bloc, Gorbachev's unexpected reversal on a major U.S.-Soviet agreement undercut his own long-term goals of buttressing the Soviet Union's reputation as a reliable negotiating partner, some western diplomats said. "What will U.S. senators think when time comes to ratify any arms control treaty?" a diplomat asked.

Most important, Moscow apparently miscalculated the possibility that Reagan would agree to new compromises on his Star Wars program under pressure. U.S. officials already have ruled out the possibility. "If Gorbachev thinks that Reagan will change his position for the chance of having a summit, he's wrong," a U.S. official here said.

A month after the Soviet leadership signed an agreement to set the dates for a summit during Shultz's visit to Moscow, Gorbachev reneged without warning yesterday and suddenly added as a condition for the summit progress on talks to limit Reagan's Strategic Defense Initiative (SDI) to place in space elements of an antimissile defense system, known as Star Wars.

According to western and Soviet officials here, the sudden hardening was based on an assessment in the Kremlin that a summit is the only bargaining chip left in Moscow's bid to prevent the United States from developing SDI weapons to the stage where they could be deployed.

The last-minute reluctance to come to Washington also represents bitterness at the critical reception that the Reagan administration has given to Gorbachev's reform policies, including a general attempt at forging a new detente, some analysts said.

Nonetheless, western diplomats consider Gorbachev's move to be so atypical of the Soviet leader, who has favored a high-profile policy of public diplomacy and holding to agreements, that they speculate that he was forced in the past few weeks to harden his stance vis-a-vis the Reagan administration by military leaders or more conservative Kremlin officials.

Although Gorbachev made similar last-minute demands at the summit in Reykjavik, Iceland, a year ago, he avoided major criticism by highlighting new Soviet arms-control proposals made there and thus avoided major criticism for backing out of an expected arms accord.

Despite the view that Gorbachev buckled under to domestic pressures to stiffen the terms for a summit, however, the new stance seems to be the climax of a carefully orchestrated campaign to force the Reagan administration into concessions in its plans to build the SDI space-based defense shield against nuclear weapons.

Ever since Shultz's visit to the Soviet capital in April, for instance, Moscow has broached the possibility of discussing general principles on SDI, cuts in strategic nuclear missiles and other disarmament topics at a summit meeting -- in addition to signing an Intermediate-range Nuclear Forces (INF) treaty to ban medium- and shorter-range missiles.

In May, Soviet officials gave the Reagan administration a draft document on general principles on SDI and other issues that they proposed would be signed at a summit, according to Soviet officials here.

The United States apparently declined the proposal, however, and Moscow temporarily abandoned the idea. Instead, Soviet officials held out the promise of a summit in Washington that would be used largely to sign the INF treaty, followed by a later summit to address other issues. Meanwhile, the Kremlin drafted several proposals that appeared to bring the two sides closer to agreement on which missile systems could be tested under the 1972 U.S.-Soviet Anti-Ballistic Missile (ABM) treaty. Shevardnadze presented the proposals to U.S. officials during his trip to Washington last month.

During that visit, Shevardnadze also signed an agreement that Reagan and Gorbachev would hold a summit this fall and that the dates of the meeting would be determined this month in Moscow during Shultz's visit.

Until the end of a 4 1/2-hour meeting between Shultz and Gorbachev yesterday, U.S. officials here say, the Americans were still under the impression that reaching agreement on the INF treaty would be enough for a summit.

But three hours into the meeting, Gorbachev told Shultz that he was not comfortable setting the dates for a summit because of lack of progress in talks to strengthen the ABM treaty and to cut the strategic arsenals of both countries, a U.S. official here said.

Even before Shevardnadze returned to Moscow after his U.S. trip, however, the plans for a fall summit seemed to be going sour. The Soviet media gave only scant mention to the Shevardnadze agreement, and this was widely viewed here as an indication that the arrangement was not received warmly by the Soviet leadership. While officials in Washington were making tentative plans for a Gorbachev trip to the United States over Thanksgiving, Kremlin officials were finalizing plans for meetings in Moscow between the Soviet leader and leaders of Australia and Portugal during the last week of November.

According to western diplomats and some Soviet officials here, the Kremlin viewed the U.S. reluctance to agree to a document on general principles on SDI and other issues as a sign that Moscow might never obtain an accord on SDI and strategic cuts from the Reagan administration.

With Reagan to leave office in a year and with mixed signals coming out of Washington about whether the Senate would ratify either an INF or a strategic arms treaty, the prospects for the long-sought accord on SDI apparently seemed even bleaker to Soviet officials.

Public criticism by Reagan and some his key aides of Gorbachev's reform policies also have struck Soviet officials as out of sync with the tide of rapprochement between the two countries. The Soviet news agency Tass quoted Gorbachev as telling Shultz yesterday, "The American leadership, contrary to public declarations and assurances made officially, sticks to a course of kindling mistrust and suspicion and cultivates the 'enemy image' with regard to the Soviet Union."

To a westerner without direct information about Politburo decisions, it seems that doubts about the chances of clinching an SDI agreement after a Washington summit led to a high-level decision to hold the meeting hostage to an agreement to reduce strategic arms and limit Star Wars research by "strengthening" the ABM treaty.

While an INF treaty might temporarily boost Gorbachev's prestige at home and abroad and enhance ties with the West, only an accord to curb space defense testing would be in keeping with his longer-term goal to cut back on costly defense programs in order to develop and revive the civilian Soviet economy.

With Reagan facing domestic and foreign policy crises and anxious to become the first U.S. president in nearly a decade to get a major arms control treaty signed and ratified, the bid seemed worth an effort, according to one Soviet view.

"If it failed," said one senior western diplomat, "Moscow could still sign an INF accord. If it worked, Moscow would succeed in its overall plan of avoiding the investments needed to match the Reagan administration's Star Wars research."