The Reagan administration has under consideration a number of undisclosed actions it might take to put pressure on Poland and the Soviet Union should Polish authorities destroy the Solidarity trade union movement.
But for the moment, the administration clings to a glimmer of hope that those authorities might stop short of crushing Solidarity and instead reach an accommodation with the union movement. That hope is based in part on the belief that the influential Roman Catholic Church in Poland has yet to fully play its part in moderating the Polish crisis.
The difficulty for the administration is taking action at a time when the situation in Poland is ''extremely fluid,'' in the words of a number of officials. The dilemma for the administration is in considering moves that, while meant to punish Polish authorities, would end up punishing the Polish people.
In the midst of this agonizing uncertainty, the administration is attempting to keep the NATO allies together so that when the time comes to act, they will be able to act in concert. The allies appeared to be in close agreement on what to do if the Soviets invaded Poland. When it comes to the gray area of a Soviet-supported Polish crackdown, a NATO response becomes more difficult.
Despite allegations made last week by Assistant Secretary of State Richard N. Perle, who left the impression that the allies had done little to coordinate strategy in this gray area, State Department officials insist that a number of possible measures have been agreed upon. Assistant Secretary of State Lawrence S. Eagleburger was flying to Western Europe Dec. 20 to further coordinate strategy.
State Department officials also deny Mr. Perle's allegation that the US was surprised by the Polish crackdown. They say the only surprise was the timing. No intelligence agency could be expected to predict the timing of such an event, these officials argue.
''Nobody would know that unless (Polish leader) General Jaruzelski was working for the CIA,'' says a State Department official.
A senior State Department official says, meanwhile, that the State Department - in discussion with the West European allies - concluded over the past six months that Soviet intervention of a ''drastic kind'' was less likely than a crackdown by the Polish military. What was considered likely now was a kind of ''creeping'' Soviet involvement or a Soviet intervention ''by proxy.''
Nonetheless, there is still a potential for differences among the allies as to how they might respond.
Some in Europe say that General Jaruzelski is merely a Polish nationalist who has acted to preempt Soviet involvement. That attitude is not shared by the State Department. The feeling here is that Jaruzelski would crush Solidarity if he could get away with it. At the same time, however, the general knows that if he goes that far he will risk the loss of Western aid and loans that are needed to keep his nation's weakened economy functioning.
At the same time, loans to Poland from Western Europe - and West Germany in particular - are much larger than those extended by the United States. Thus, the West Europeans might tend to be more cautious in applying pressure involving such loans than would the Americans.
Other officials indicate that a halt to the nuclear arms talks with the Soviet Union in Geneva also is under consideration should suppression in Poland continue.