The comparative ease with which Poland's military authorities were able to quash antigovernment demonstrations in more than a dozen cities and towns this week illustrates the failure of the suspended Solidarity trade union to devise an effective strategy for combating martial law.

Underground activists staked a lot on the success of the demonstrations, which were called to mark the second anniversary of the Gdansk agreement that gave birth to Solidarity. It was hoped that, if a substantial proportion of Solidarity's 9.5 million members had shown up on the streets for organized rallies, this in itself would have forced the government to the negotiating table.

The turnout, however, was poor -- and the Communist authorities now seem less willing than ever to negotiate with Solidarity's elected leadership. The regime has indicated that it may use the occasion as a pretext for cracking down even harder on Poland's once formidable dissident movement and punishing young people who, it is claimed, made up the bulk of the demonstrations.

"Remember the Reichstag fire," said a Polish journalist recalling how Adolf Hitler used the burning of the German parliament in 1933 as an excuse for suppressing remaining opponents.

In fact, the freedom of maneuver of Poland's military leader, Gen. Wojciech Jaruzelski, is more constrained than this rather unfair analogy might suggest. He has shown convincingly that, in the short term at least, his government can maintain control in the streets and factories thanks to its immense logistical superiority over a fragmented underground. But there is no evidence that he is any closer to winning the hearts and minds of his fellow countrymen or to his declared intention of creating a reformed political system capable of operating on a basis of popular consent.

The result is that, nearly nine months after the imposition of martial law, he must still tread a very careful path between too little and too great repression. On one hand, he is determined to convince Poles that further opposition is pointless and to take advantage of a growing cynicism about politics. On the other, he knows that if he pulls the noose too tight, the current apathy may turn to one of blind anger born of despair.

A communique issued by the ruling Military Council of National Salvation, which met Wednesday to consider the street disturbances, called for the speedy indictment of dissident leaders from the workers' defense group known as the Committee for Social Self-Defense (KOR), who are already under investigation for forming a political party. The military council also ordered the minister of education to consider disciplinary action against students -- a sign that the government intends to tighten its control over universities and high schools.

Political analysts here believe that the moves against KOR could form part of Jaruzelski's mas- ter plan of breaking the alliance of workers and dissident intellectuals that had made Solidarity such a potent force. Purged of anyone connected with KOR or other dissident groups, a restructured trade union movement would be much more amenable to Communist Party control.

In the meantime, the government has been refining its policing methods to enable it to deal with successive challenges mounted by Solidarity. By contrast, the union has repeatedly made the classic mistake of preparing to fight its last battle -- rather than the next one.

In imposing martial law, the authorities discovered the answer to Solidarity's favorite weapon, the peaceful occupation strike. Last December, one strike after another was broken by elite squads of riot police who stormed factories isolated from one another by curfews and communications blackouts.

Next the government found out how to deal with so-called Italian strikes -- a euphemism for goofing off -- and token stoppages. They placed workers under military discipline and drafted plainclothes security men into the factories to stifle any protests. Workers who refused to obey orders were either laid off or arrested.

The difficulty of organizing strikes within factories forced Solidarity leaders to consider street demonstrations where protesters would at least be anonymous. But the government now seems to have found that it can combat this form of protest by mounting a huge propaganda campaign based on fear to dissuade the rallies and then swamping demonstrators with vast numbers of riot police and soldiers.

In an article for a clandestine news bulletin written last month, the head of Solidarity's Warsaw chapter, Zbigniew Bujak, described the demonstrations as a possible turning point. If the authorities showed that they were capable of dealing with the challenge, he wrote, it would mean that Solidarity would have to turn to less radical forms of resistance to martial law.

The events of the past few days seem to have borne out Bujak's fears. His own preference is now likely to be for a strategy of long-term resistance to Communist rule based on boycotting official institutions and creating what has been described as "an underground society."

The strategy, however, depends for its success on the nature of the opponent. When the authorities are determined to impose their will, as Jaruzelski's government evidently is, nonviolent protest can be ineffective.

The only obvious alternative, however, is terrorism. There is evidence that some small breakaway groups have begun to dabble in terrorist methods -- but this is a path that has been rejected by all responsible Solidarity leaders.