This week's intensified war of nerves throughout Eastern Europe is the final attempt by Poland's allies to pressure Stanislaw Kania and his Polish Communist Party colleagues to scale down their plans for liberalization in the party, restore a measure of party discipline and deal firmly with Solidarity, the independent trade union federation.

If the pressure works, the Soviets are prepared to accept Solidarity, so long as it does not challenge the political primacy of the party, and treat Poland as a special case in the Soviet Bloc, some Western analysts here believe.

Like good poker players scenting weakness around the table, the Soviets flashed a peek at their ace in the hole -- a possible military intervention -- through the extended Soyuz 81 Warsaw Pact maneuvers. With that card not yet revealed, this week's hand opened with the emphasis on political pressure -- a hand, analysts feel, the Kremlin would want played out before deciding to turn over its ace.

Soviet President Leonid Brezhnev's conciliatory speech at the Czechoslovak Party Congress in Prague today and the end of the Soyuz war games in and around Poland now appear to offer a period of respite for the beleaguered Polish leadership, which has been subjected to repeated public warnings by its allies for the past week, reflecting a newly concerted Soviet Bloc stand.

Even maverick Romania is showing less understanding for the Poles now, expecting Kania to deal firmly with the independent Polish unions, although still professing opposition to a Warsaw Pact military intervention. Hungary which until March 29 showed distinct sympathy for Poland, is now echoing the Soviet media and speaking for the first time about "antisocialist" and "counterrevolutionary" forces within the Polish labor movement.

But while appearing to gain time, Kania has not gained the full confidence of his Pact partners. That was clear from several major pronouncements in recent days, including Brezhnev's speech today.

In the arcane world of communist code words, Brezhnev voiced support for "Polish Communists" -- not the Polish Communist Party -- and expressed confidence that they would be able to resolve the crisis without outside interference.

Speculation about Moscow's intentions should be set against developments of the past nine days, including the first purge of Solidarity militants by moderate union leader Lech Walesa and, more important, the first well-defined and publicly stated split in the Polish Politburo.

The division in the union, according to the analysts here, was seen in Moscow as an opportunity for the Polish Communists to regain some of the ground lost in dealing with Solidarity over the past seven months.

The division in the Politburo, which surfaced during the last meeting of the Polish Central Committee, is regarded as even more important because it produced several well-known personalities as an alternative to Kania, to the prime minister, Gen. Wojtiech Jaruzelski and other reformists.

A group in the Polish leadership -- led by Politburo members Stefan Olszowski, Tadeusz Grabski and Andreej Zabinski -- was able openly to formulate a program of action different from that espoused by Kania and the reformist majority.

According to analyst Jan de Weydenthal of Radio Free Europe, a U.S. founded operation that beams programs and news into Eastern Europe, the fact that the hard-liners challenged the majority by offering their resignations and that these were not accepted is a sign of Kania's weakness.

The emergence of Olszowski and his colleagues gives the Soviets and opening to support that group "without being open to charges that they are interfering in Poland's internal affairs -- merely stating their preference for views legitimized by the Polish party itself," Weydenthal said.

According to speeches and articles monitored over the past week, Olszowski has continued to publicly assert his views. He warned that Poland was becoming a "weak link" in the Warsaw Pact, argued for the need to stifle the Polish media and asserted he would "never" be indulgent on the issue of publishing anti-Soviet material."

The existence of a hard-line alternative and the divisions within Solidarity are now expected to be exploited by Moscow and its allies in the pending political struggle, the focus of which will be the Polish party itself.

The prevailing view among analysts here is that the issue of new party election rules -- rather than anything Solidarity may do, short of mounting a general strike -- remains the crucial problem on which the ultimate Warsaw Pact attitude toward Poland will be based.

The Soviets are believed prepared to go a considerable length toward reaching a political resolution that would meet their basic demands -- a Socialist Poland within the Warsaw Pact that enjoys a unique status. As long as the Polish party is perceived as loyal to Moscow, the Soviets seem willing to accept some form of independent trade union in the hope that, at a minimum, they would be able to minimize the effects of the Polish experiment on other bloc countries.

In this context, the coming three weeks of political activity in Poland before the next Central Committee meeting are seen as crucial. Despite military preparations, most observers here believe that a military intervention is not imminent.