Foreboding silence from Moscow, following strong earlier hints that Foreign Minister Eduard Shevardnadze would arrive here this week, threatens plans for Ronald Reagan to meet Mikhail Gorbachev in a Washington treaty-signing summit this fall.

U.S. arms negotiators were informed in June that Shevardnadze's long-awaited trip to see Secretary of State George Shultz would probably take place July 13 and 14. But since then, Shevardnadze has said not a word about coming here. Reinforcing the silence, Soviet arms negotiators in Geneva have suddenly halted progress on the new intermediate-range missile treaty (INF), cutting the heart out of the administration's hopes for a major foreign policy triumph.

Administration officials admit not knowing Moscow's mind. But raising major concern among them is escalation of Kremlin demands for removal of 72 old Pershing I missiles as part of the INF package. That is a high-stakes poker game based on Soviet perception that the beleaguered president cannot say no.

A Soviet stall at the Geneva nuclear talks started three weeks ago, when detailed treaty-drafting sessions ended. Some real progress had been made in matching similar Soviet and U.S. provisions, studying delicate translation issues and trying to resolve Moscow's demands for 100 residual INF warheads each side could keep -- but which the United States does not want.

The new freeze is also evident in Soviet refusal to produce the long-awaited text of its strategic arms treaty for reduction of long-range missiles. U.S. negotiators expected it long ago. That is one more sign that unless Shultz gets an acceptance soon from his colleague Shevardnadze, Reagan may not be seeing Gorbachev at all -- this fall or ever.

The Pershings belong to West Germany, but their nuclear warheads belong to the United States. Washington's official position is that this is strictly German business. That is true even though Moscow may be playing hardball in trying to force a political crisis in the Federal Republic, disrupting Bonn's coalition government that is split between conservative Chancellor Helmut Kohl and liberal Foreign Minister Hans Dietrich Genscher.

If the Pershings stay, Bonn would be blamed for collapse of the INF treaty with these probable results: the German and West European peace blocs ignited; the split between Europe and the United States widened; Kohl targeted by the peace bloc. But if Kohl is persuaded to yield and allow the destruction of the Pershings, he would lose his hard-core political support and descend into political oblivion. West German power would revert to the de'tentist left.

Soviet arms control negotiators are zeroing in on the German Pershings, one high State Department official told us, ''making it a much more important factor that they've suddenly decided to take advantage of.'' Exploiting memories of Hitler's invasion of the Soviet Union in June 1941, the Kremlin is trumpeting its new message: the proposed new zero-zero INF treaty will wind up not zero-zero but zero-72 if the Pershings stay.

That could be a treaty-wrecking charge. Or it could be a typical Soviet delaying move to make the weakened Reagan pay more for the treaty that he and Shultz so avidly pursue as they try to rise from the Iran-contra maelstrom. The autumn summit has become important as a scene-changer putting Reagan on the high ground of grand diplomacy.

But Gorbachev is tantalized by rewards in scuttling the INF treaty, which might reduce his own major political problems as he tries to reform Soviet society. Plunging West Germany into political crisis and splitting the NATO alliance would soften up Europe and weaken its resistance to giving Gorbachev economic advantages he desperately needs to carry out his reforms. It would also demonstrate the lame-duck Reagan administration's inability to carry out what has become the most important single element in its foreign policy: the new INF treaty.

State Department aides flatly deny charges from elsewhere in the administration that Shultz is quietly pressuring the West Germans, through his close friend Genscher, to go along with the Soviet demand on the Pershings. The secretary is reported ''absolutely hands off'' on either pressuring Kohl to yield or pressuring Genscher to stand fast with Kohl against the Soviet demand.

Shultz is even neutral about Kohl's demand that West Germany has the right to upgrade the old Pershings. Diplomatic sources say privately he will support that demand if the Pershings survive the Soviet onslaught.

But the judgment in the Kremlin may be a different reading of Shultz. If it is seen there that Reagan needs a summit more than Gorbachev, the Soviets will press hard on the Pershings, forcing Reagan to choose between a treaty that raises havoc in West Germany or no treaty and no summit. No wonder Shevardnadze's absence from Washington's muggy summer is cause for anxiety.