When President Reagan imposed trade sanctions against the Soviet Union in response to the Polish crisis, it was not exactly a daring innovation in foreign-policy tactics. Presidents of both parties have tried many times to influence the behavior of other nations by cutting off or restricting the flow of goods and money from the United States.

Countries at every point in the political spectrum, from South Africa to North Korea, have been denied access to American-made industrial products, food and raw materials because their domestic or foreign policies were out of step with Washington's.

Now the Reagan administration's tactics have rekindled an old, more or less continuous debate among scholars, economists and foreign policy specialists about the wisdom and effectiveness of using economic restrictions as an instrument of foreign policy. The issue is whether the message delivered justifies the damage to the U.S. economy.

Even before the martial law crackdown in Poland, the expansion of U.S.-Soviet trade that began in the heyday of detente a decade ago had been halted in response to the Soviet invasion of Afghanistan. Now the administration is trying to limit Soviet access to U.S. technology and petroleum equipment and to reduce the benefits Moscow derives from trade with the West.

The United States, arguing that the Soviet Union is bent on repression in Eastern Europe and military expansion that threatens Western security, is expected to press the Western European allies to join in the restrictions at a meeting in Paris on Tuesday of their Coordinating Committee on Export Controls.

"We are pledged," Assistant Commerce Secretary Lawrence J. Brady said last week, "to limit the direct and indirect contributions made by our resources to the Soviet military buildup, and we are pledged to substantially reduce Soviet leverage over the economies of the non-Communist world."

Brady's speech to the National Association of Manufacturers was a cold-war stem-winder, in which he said that the Soviet Union has "created a veritable 'Soviet lobby' in Western business and government circles" that seek trade with communist nations at the expense of Western security interest.

He said the benefits of East-West trade have flowed only eastward, and he recalled "the words of Vladimir Lenin, founder of the Soviet state, who prophesied that the capitalists would gladly sell the rope with which they would be hung." The Reagan administration, he said, is committed to cutting off trade that would contribute to Soviet state power.

Even among those who support that policy, there appears to be widespread agreement that, in the short run at least, no trade or economic restrictions, whether supported by the allies or not, will change Soviet behavior in Poland any more than they did two years ago in Afghanistan. A total trade ban enforced against China for more than 20 years cut off U.S. access to that vast market without redirecting Chinese policy, and Cuban troops are still in Angola despite the longstanding U.S. ban on commerce with the Castro regime.

The issue is not whether sanctions will "work" in the sense of restoring the situation in Poland to what it was before martial law was imposed, because it is understood that they will not. The debate is over whether Washington ought to drop the sanctions entirely because the only victims are U.S. firms; stick to them as a matter of principle, or expand them in the hope that a long-term economic squeeze will influence Soviet policy.

Some critics have said that the United States resorts too quickly to economic sanctions because it has no confidence in diplomacy. Others argue that sanctions can be and are effective, and criticize Reagan for not going far enough. And still others oppose sanctions because they feel the restrictions damage U.S. economic interests without achieving their foreign-policy objectives. The latest sanctions, for example, will cost the Caterpillar Tractor Co. an $80 million sale of pipelaying equipment and will wipe out a $175 million sale by General Electric Co., just as the Boeing Corp. lost a major contract with Libya when the Carter administration banned the export of jumbo jets to that country in 1978.

"The United States still treats trade with other countries as if it were a favor to them," said Dimitri K. Simes, a Soviet-born scholar who is directing a study of U.S. trade sanctions against Moscow at the Johns Hopkins University School of Advanced International Studies.

"What does this say to the Soviet Union?" Simes asked. "It says that there is a unique American propensity to use economic sanctions to send signals. You have done it in South Africa, Libya, Chile, and to what effect? Should this always be first on the signal-sending list?"

A major problem, Simes said, is that unlike the boycott of the 1980 Moscow Olympics, which became moot when the games were over, trade sanctions remain in place indefinitely. If they are reevaluated or lifted, he said, it sends "other signals" to the target country.

The prime example, he and others said, was the partial embargo on grain shipments that former president Jimmy Carter imposed after the Soviet invasion of Afghanistan. Reagan came into office pledged to lift it, and he did--thereby, according to Simes and other critics, giving the Soviets a free hand in Poland and sending the "wrong signal" to the European allies whom the administration was trying to push out of a major deal to import Soviet natural gas through a pipeline from Siberia.

The use of export restrictions to advance political or strategic interests has been a feature of U.S. policy for many years. Congress permits the president to ban or restrict exports for reasons of national security, domestic shortages, foreign policy--including human rights--and nuclear nonproliferation. Export licenses are required for a vast array of goods, and some goods are licensed selectively according to the country of destination.

Police equipment and computers, for example, cannot be exported to South Africa if the government thinks they will be used to support that country's apartheid system. Helicopters and jet planes cannot be sent to Iraq, Syria or South Yemen because the State Department says they encourage international terrorism, and no aircraft may be exported to Libya. Cuba, Cambodia, Vietnam and North Korea are subject to virtually total trade bans.

The Commerce Department's long list of controlled commodities includes machine tools, petroleum production equipment, drill presses, wind tunnels, cryptographic equipment, mobile crime labs, nickel, beryllium, boron, explosives, polymers, synthetic rubber, Western red cedar lumber, and horses. Some can be exported only to countries where there are virtually no restrictions, such as Canada; others may not be exported at all.

The most controversial restrictions have been those adopted for political reasons, especially when the United States acted unilaterally, as it did against the Soviet Union. Critics of the sanctions say they are useless if the embargoed goods can be obtained elsewhere; supporters say the political gesture is more important than the actual effect on the target country.

"Sanctions are almost always applied for political reasons," said a former U.S. ambassador who now represents business interests. "Very few organizations with an economic orientation approve of this kind of activity. Very few with a political or foreign policy orientation are willing to rule them out. The question always is, which part of society is going to pay the price? You know that you are going to hurt yourself at the same time when you make a decision like this, but that is what a president has to do--you have to lead your own country."

Referring to the sanctions imposed by Carter over Afghanistan, he said, "Were the grain embargo and the Olympics boycott a success or failure? We had to show that we were prepared to take strong action even if parts of our own society would suffer."

Lawrence Fox, a former Commerce Department export control official who is now vice president for international affairs of the National Association of Manufacturers, said the NAM "doesn't like to see American manufacturers hurt. We're not keen to see foreign goods replace ours in trade, but this has to be seen in context. What would you have the U.S. do?"

He said firm action by the United States could stiffen the attitude of the Europeans, and "under the circumstances, this response gets an A on the report card. If you expect the Soviets to change their policy in the short term, that's unrealistic. The question is, will this and subsequent steps offer the possibility of more restrained actions in the future? We don't know, but it's the best we could devise under the circumstances."

New York investment banker Felix Rohatyn is among those who argue that if the administration's intention is to put real pressure on the Soviet economy, rather than just to make a statement, trade sanctions are inadequate. He argues that the United States should cut off the bank loans and credits that have sustained the economies of the Eastern European countries and force the Soviet Union to pick up that burden.

"It is easy for the Soviet Union to get around a grain embargo," he wrote in the New York Times, "for Argentina and other countries will be glad to accommodate. Trade and economic sanctions are hard to impose since many European countries choose not to follow. The withholding of capital is a different issue, however . . . the West has been relieving the Soviet Union of what may be its greatest shortage--capital--at the cost of making bad loans while pretending to oppose communism. That is bad business, bad policy, bad morality."

Richard Davies, former U.S. ambassador to Poland, shares the administration's view that the Soviet Union has failed to live up to its half of the detente bargain and violated the principles of the Helsinki declaration, but he urged Reagan not to stop at the measures of "middling seriousness" adopted so far.

The United States and its allies now face the choice, he said, of taking "the easy way out," ensuring further "serf rebellions" in Eastern Europe that threaten world peace, or of cutting off all trade and commerce, including grain exports and the gas pipeline.