A Pentagon official acknowledged yesterday that the U.S. government had suffered "a collective failure" of intelligence gathering and assessment by failing to anticipate that the Polish army, rather than the Soviet army, would crack down on the Solidarity union movement inside Poland.

"We were take by surprise," said Richard N. Perle, assistant secretary of defense for international security policy. "This has significant implications for a lot of assumptions we make about the kind of warning that is likely to be available to political-military crises.

"We base a lot of our defense capability on the assumption we would have a number of days warning," Perle continued. Failing to read the danger signs correctly in Poland indicates that the U.S. government has been making "overly optimistic assumptions" about its ability, "especially in a protracted crisis, to anticipate the date and time of events," he told a breakfast meeting of reporters.

Perle said the Soviet invasion of Afghanistan in 1979 also was a surprise to the United States government.

Asked if the military or the Reagan administration was at fault for misreading events in Poland, Perle responded that "it was a collective failure. In our concern to deter direct Soviet military involvement, we didn't give sufficient consideration to the use of Polish forces to accomplish the same purpose, that purpose being to crush Solidarity."

He did not pin the blame on any intelligence organization specifically and acknowledged that in trying to assess events unfolding in Poland "we weren't asking the right questions. We could be less sure of ourselves," said Perle of the future, "and should be."

Now that the Polish army has made its move, the U.S. government still is pretty much in the dark about what really is happening inside Poland, Perle said. This is handicapping the administration's efforts to decide on the proper responses to the crisis, he said.

Perle said that the Polish government has blacked out internal communications within Poland and that satellite photos are proving of little value to U.S. analysts, partly because the weather has been poor.

Perle said the sanctions that the administration had thrashed out in advance of the Polish crisis were tailored to the Soviet Union sending in its own troops. This has not happened yet, and Perle stressed that the administration is taking pains to avoid setting off that action.

He said what the United States does will depend on how violent the suppression of Solidarity becomes and whether Soviet troops move in behind the Polish ones.

He said postponing the resumption of U.S.-Soviet talks in Geneva on the mutual reduction of nuclear weapons in Europe was an option the administration was considering.

Looking at Solidarity's longterm prospects in Poland, Perle said: "It would not surprise me if there were a reconstitution of Solidarity in the aftermath of this action" because of "the broad base of support" it enjoys.

Turning to Israel and its seizing of the Golan Heights, Perle said the Israeli government's "insensitivity to U.S. concerns is a very dangerous course to pursue."