In early September, when key Politburo member Stephan Olszowski is known to have urged the Polish army to "deploy" against striking workers in industrial Silesia, he was brought up short by Gen. Jaruzelski.

"That will make fortresses out of all our factories," Poland's top general said abruptly. "How can we attack so many fortresses?"

The general's shrewd veto was instantly recalled by one insider here when the "military council," a body unnoticed for the past 20 years, issued its veiled, page-one warning of "serious dangers to functioning of the state" immediately after last week's crucial Central Commitee session.

Put in the perspective of the general's earlier veto, the shrouded warning of military action to control runaway strikes looked like a bit of fakery. In fact, however, it served a purpose in the counterattack strategy of Communist Party leader Stanislaw Kania. That purpose has little to do with army strike-breaking. Rather, it seems part of a master plan to use fear as one way of cooling passions in the electrifying, still-peaceful Polish revolution Moscow views as potentially the most serious threat ever to its European empire.

Other elements of Kania's campaign to reassert party power over Poland's torn society were apocalyptic declarations seldom voiced by any government. The "appeal to the Polish people" by ruling Communist Party's Central Committee warned that "the destiny of the nation" is at stake as "protracted unrest is driving our homeland to the verge of economic and moral destruction." u

Likewise, Kania's own speech to the Central Committee's plenary session last week was loaded with spicy rhetoric. He charged that some of the striking "Solidarity" worker groups "have been penetrated by groups connected with the centers of imperialist subversion abroad." These unidentified groups "want to disassemble, undermine and overthrow Poland's socialist [Communist] statehood," he said. He sprinkled his text with words like "anarchy" and "counterrevolution."

There is ample reason for Kania and his new, vastly toughened Politburo -- brought to the top of the party last week -- to issue such dire warnings, even though the last 10 days have produced no new crisis. Indeed, strike leader Lech Walesa sold his regional Solidarity chiefs on a strike moratorium during the month of December. There was no major work stoppage or disturbance anywhere in Poland this past weekend.

But Kania and the Politburo are looking ahead. Future demands are predictable from Solidarity, and its legions of allies among intellectuals for extending their stunning gains on the free-union front to democratization of the decrepit economic system and the Communist Party itself. "We want to correct the wrongs in our society," one strike leader told us.

Despite the Dec. 5 secret Moscow session of Warsaw Pact heads of state disavowing all intervention. Kania knows that if the clean wind of freedom ever gains force enough to undermine the "leading role" of the Communist Party, all bets are off.

So, to prepare for hardships ahead, Kania is using heavy propaganda to instill fear and warn against crossing unacceptable lines. He is also pumping belated new life and force into his party from the top down. At least 16 regional party leaders have been summarily fired and a campaign to put new Communist blood into local party cadres is under way. He has already replaced about 500 of the 2,500 top industrial and agricultural managers to shake up the most badly managed and dangerously depressed economy in the Warsaw Pact.

Finally, backed by new Politburo strong-man Mieczyslaw Moczar and holdover Olszowski, Kania is plotting to weaken Solidarity by splitting it along ideological and, more important, regional lines, exploiting the differences among worker groups in Gdansk, Solidarity's courageous leadership, starting with Walesa, the strategy, in the words of one of them, is to "smother us by taking us in and making us share in their decisions."

With talk of Soviet intervention quieted for now, Kania's desperate efforts might just succeed in reviving party rule in a way that seemed improbable short weeks ago. At the very least, he has grabbed the offensive and, for now, appears to be controlling events, using fear as one weapon in his formidable arsenal.