To what purpose?

On Dec. 13 last, Polish tanks ended political pluralism in Poland.

On Jan. 17 former Secretary of State Henry Kissinger complained that ''freedom-loving Poles who looked West saw dithering procrastination, sophisticated justification for impotence, or rhetoric incapable of rising to serious action.''

Last Saturday, Jan. 30, the United States International Communications Agency , which runs US overseas propaganda, mounted a TV program called ''Let Poland Be Poland.'' It was beamed all over the world and, by special dispensation from Congress, was allowed to be seen in the US. It was informational, if repetition of unpleasantness by the Polish government to Poles is informational. It expressed indignation.

But reports indicate that the TV program and various rallies scheduled for the same day to advertise the free world's disapproval of what the Polish government has done to Poland played to small and not notably vociferous crowds. As theatrical productions go it was no smash hit.

There were some riots in Poland on that day, Jan. 30. Some 14 persons were reported injured. Reports from Poland indicated that the rioting was mostly done by students in Gdansk. Some reports indicated that the riots were in anticipation of heavy price rises which were due to be applied all through the Polish economy begining on Feb. 1.

But when the new high prices went into effect on Feb. 1 reports from Poland indicated an apathetic reaction. Lines at food shops were shorter. Many looked at the new prices, up as much as five times over for some items, and walked away. There were no reports of rioting over the new prices on that first day.

Meanwhile the US and its NATO allies continue to hold meetings over possible further sanctions to be applied either to Poland or to the Soviet Union or both. Some slight progress toward tightening bans on shipment of items of potential military value to the Soviets is reported. The US is still fumbling with ideas on how to prevent the building of the gas pipe line to carry Soviet gas to Western Europe, primarily to West Germany.

But all efforts by the US government to work up a coordinated NATO program of toothed sanctions continue to founder over the refusal, so far, of the Reagan administration to offer to embargo the shipment of US grain to the Soviets.

The Europeans, understandably, distrust sanctions at their expense. There is much talk of ''equal sacrifice'' sanctions, meaning sanctions which would hurt US exporters as much as the European exporters. Washington continues to be eager to punish Moscow at the expense of the European allies. So far as I can discover there is no serious thought in Washington of adding to the current surplus of grain in US granaries in order to punish the Soviets for having pushed the Polish government into suppressing political pluralism in Poland.

So, at the end of eight weeks of martial law in Poland, the Reagan administration in Washington is still using ''rhetoric incapable of rising to serious action'' in place of serious pressures on the Soviet Union.

What good is it doing?

It is not influencing Moscow in any visible way.

It is not influencing the military government in Poland in any visible way.

It did reduce from two days to one day the duration of the recent meeting between US Secretary of State Alexander Haig and Soviet Foreign Minister Andrei Gromyko.

It has deferred the scheduling of new negotiations on limiting strategic weapons.

But the effect of these last two ''achievements'' is to put further strain on the ties which bind the alliance. They certainly mean nothing in Poland and next to nothing in Moscow. They just might wipe out what chance there still is of some new type of agreement on limiting nuclear weapons during the life of the Reagan administration. If anything happened to Leonid Brezhnev before such talks got going, and approached a conclusion, there would undoubtedly be a long delay before they could ever get started up again.

A new regime in Moscow would be unable to work out a negotiating position on nuclear weapons until the new men had settled in and a new leader had appeared. It took a long time for Moscow to work its way from Stalin to Brezhnev.

So there continues to be much fuss and fury of rhetoric in Washington about doing something to help the Poles. But the essential fact remains that the future of Poland is being worked out in Poland by the Polish people themselves. Washington would do just as much good, or harm, by saying nothing.