Sixteen months ago, when the Polish labor union Solidarity was born, many Western experts and Polish dissidents believed a confrontation between the union and the Polish government was inevitable.

But for nearly a year, both Solidarity and the regime took great care to prevent such a conflict, and in the last few months many observers began expressing hope that a clash would not come.

Those hopes were dashed early Sunday morning, when Polish security troops raided Solidarity's Warsaw headquarters and arrested union officials across the nation. Within hours after the crackdown began, Polish premier Gen. Wojciech Jaruzelski declared a state of national emergency and imposed martial law.

Reports filtering out of the country were sketchy because of a nearly complete communications blackout. The regime halted telex and telephone communications when the crackdown began and grounded all flights to the West. Later in the week, the Associated Press, Reuters, and other Western news agencies also lost their communication links with Poland.

Nevertheless, some news did get past the borders, and initial reports put the number interned at about 1000. On Tuesday, Solidarity sources said at least 3000 union members had been arrested in Warsaw alone, and by week's end as many as 45,000 people were reportedly under arrest throughout the country.

Solidarity immediately retaliated with some members calling for a general nationwide strike. Although the strike at first failed to materialize, within a few days sit-ins and work-stoppages began to spread.

In an attempt to tighten its control of the nation, Poland's ruling military council issued a new series of decrees, putting some factories under the army's control, banning some newspapers, outlawing the sale of gasoline (which can be used in hand-made bombs), and prohibiting the sale and consumption of alcohol.

The regime also suspended work-free Saturdays--a major consession won by Solidarity--and ordered Poles to resume a six-day working week. The government had long wanted to take such action to help lift the country from its economic depression.

As rumors circulated, the whereabouts of Solidarity leader Lech Walesa remained unclear. Polish officials originally said Walesa was free and had been flown from Gdansk to Warsaw to negotiate and attempt to prevent a general strike.

Later reports, however, said that Walesa was under house arrest in a government building outside of Warsaw. The Polish government did not include Walesa's name on a list of interned Solidarity leaders issued Wednesday. Polish officials said Tuesday he was psychologically broken and weeping but Solidarity sources said he remained psychologically sound.

During the first few days of the conflict, the situation in Poland appeared relatively calm, but on Wednesday the first confirmed reports of violence began filtering out of the country.

Strikers holding the Lenin shipyard in the Baltic port of Gdansk fought with security forces yesterday after Polish troops overran the installation. Warsaw radio reported 160 police and 164 civilians injured.

Meanwhile, demonstrators at a coal mine near Katowice battled police with stones, crowbars and axes yesterday. The police opened fire, killing seven protesters and wounding 39, according to Warsaw radio.

Polish archbishop Jozef Glemp issued a communique Tuesday attacking the "numerous excesses" perpetrated against striking workers, intellectuals and students. "Our suffering is that of the entire nation terrorized by military force," Glemp said.

Although the Soviet Union did not appear to be directly behind the Polish government's actions, Soviet news agencies praised the Polish government's actions. But yesterday the British Broadcasting Corporation's Warsaw correspondent reported that the Soviet commander-in-chief of Warsaw Pact forces told Poland's leaders that unless they restored order, the Soviets would do it.