Moscow — The Soviet Union is seeking to sharpen differences within the Western alliance over the military crackdown in Poland.
At the same time, the Soviets have shown a reluctance to antagonize Ronald Reagan unnecessarily. After an initial blast at the US leader for announcing trade sanctions against Moscow, the Soviet news media have gone easier on him.
A Pravda commentary Jan. 2 focused criticism on second-echelon administration officials. An article Jan. 3 held open the possibility the United States remained committed to arms talks.
The stakes in the Soviet strategy are high. Through it, the Kremlin apparently hopes to:
* Ease international pressure on Poland's martial-law rulers.
* Limit West European support for the US economic sanctions.
* Head off tougher sanctions, such as a renewed grain embargo.
* Salvage prospects for fruitful arms talks and, ideally, for cancellation of US plans to base new nuclear missiles in Europe.
* Ensure, at a minimum, that public blame for any setback to arms talks rest squarely with the United States.
Whether the strategy will work should become clearer in the days and weeks ahead. On Jan. 4, foreign ministers of the European Community are to meet in Brussels to discuss the Polish crisis and the announcement of US sanctions. On Jan. 5, Mr. Reagan meets in Washington with Chancellor Helmut Schmidt of West Germany, the most outspoken of West European states in its reservations over the US approach to the Polish crackdown.
Later in the month, the Western military alliance, NATO, is to discuss the Polish crisis.
Meanwhile, other East-West contacts are to continue. US and Soviet negotiators are still expected to resume the talks on European nuclear arms that began in November. In late January, US Secretary of State Alexander M. Haig Jr. and Soviet Foreign Minister Andrei Gromyko are to meet.
In February, the Madrid follow-up conference on the 1975 Helsinki accords is set to resume. In the spring, the superpowers are slated to begin new talks on strategic arms control.
So far, a sounding of West European and other diplomats here suggests, Mr. Reagan has been playing his cards on the Polish crisis both badly . . . and very well.
On the minus side -- the plus side, if you are a Soviet official -- the US President went ahead with economic sanctions against Moscow despite a visible lack of consensus among his European allies.
Mr. Reagan argued that Poland's rulers were snuffing out Polish freedom and that since the Kremlin had long been pressing for such a crackdown, the Kremlin must bear part of the responsibility. Many West Europeans say the Polish authorities should be given time to make good on pledges to pursue internal reform and that, no matter what role Moscow may have played in the imposition of martial law, the Soviets have at least avoided direct military intervention.
Yet on the plus side for the Americans, diplomats argue, is the fact that Mr. Reagan so far seems disinclined to make the sanctions a major issue of loyalty within the Western alliance. The Americans seem to be asking only that allied states avoid actively undermining the trade restrictions.
Most important, the President has so far signaled continued commitment to a central West European priority: arms-control and other negotiations. He has not canceled the talks on European arms, nor has he called off the Haig-Gromyko meeting, threatened to pull out of the Madrid conference, or rolled back on the decision to resume strategic arms talks. He has even suggested that a meeting with Soviet President Leonid Brezhnev remains possible.
''Reagan seems intent, so far, on making sure that if anyone calls off talks, it is the Soviets,'' says one senior West European diplomat. ''This is very wise.''
The Soviets have responded, in their official media, by in effect warning the West Europeans not to trust Mr. Reagan. ''Washington is directly blackmailing West European governments: 'Either you support the US sanctions or we will go further and stop the . . . talks on limitation of nuclear weapons in Europe,' '' said one Soviet commentary Jan. 2.
The Soviets clearly want West Europe to see things this way. Politically, this would keep strong pressure on Mr. Reagan to move cautiously on the Polish crisis. Economically, the West Europeans could prove reluctant to offer even tacit backing for the US trade sanctions.
Even such partial support - a full-scale Western embargo seems impossible, in any case, short of direct Soviet intervention in Poland - could complicate life for Moscow.
At least one item apparently covered by the US restrictions could be made only at a plant in France, business sources here say. This is a turbine rotor for European-made engines earmarked for use on a huge gas-export pipeline from Siberia. Recent news reports from Paris, though not mentioning the turbine deal specifically, say France is inclined to deter local companies from filling gaps caused by the US sanctions.