Alarm about impending radical change in Reagan administration policy was raised during the superpower summit when Mikhail Gorbachev devoted nearly an hour to secret discussions with Secretary of Commerce C. William Verity and other longtime enthusiasts of U.S.-Soviet trade.

Details never have been revealed. But shortly after the summit ended, one American participant in the trade meeting -- an intimate and close collaborator of Verity -- publicly avowed a desire to help the Soviet Union become an ''economic superpower.'' Skeptics worry that this is the real goal of Gorbachev's perestroika.

Here is the question, debated beneath the surface in official Washington: Should the United States open doors to maximum commercial and financial cooperation with Moscow, no questions asked, or insist on such preconditions as withdrawal from Afghanistan and limits on military growth?

The debate remains underground because neither Verity nor Secretary of State George Shultz, leaders in pushing toward a new detente, has shown his hole cards on trade. But backstage events during summit week signalled that Verity's dictum as an industrialist that ''trade is trade'' -- unlinked to national security or human rights -- may become government policy.

Gorbachev's private meeting at the Soviet Embassy was attended by Verity and two industrialists warmly received at the Kremlin: Dwayne Andreas, top American businessman on the U.S.-Soviet Trade and Economic Council (USTEC), and Armand Hammer, whose warm relations with Moscow began in Lenin's day.

Also on hand was James Giffen, friend and former Armco Steel colleague of Verity who is currently president of USTEC. Asked on NBC's "Today" broadcast Dec. 11, after Gorbachev had left for home, whether ''we really want to help'' make the Soviet Union ''an economic superpower,'' Giffen replied: ''I think we do.''

We asked Giffen what Verity and the businessmen said to Gorbachev and what Gorbachev said to them about what the United States should do to open trade. Hardly anything was said by either side, Giffen told us, beyond expressions of ''general agreement'' that trade should expand. But the idea that the general secretary of the Soviet Communist Party would spend nearly one hour discussing a Soviet priority issue with dedicated East-West traders and say hardly anything defies credulity.

American politicians worried about building Soviet economic power through U.S. trade suspect Gorbachev and his aides at that session laid out specific, large-scale joint ventures. But the anti-traders admit lack of knowledge. No hard plan has emerged from the Commerce Department. While not knowing what may happen tomorrow or the next day, skeptics insist the administration build self-protection into any new trade deals.

What chills them is Giffen's candid admission about making the Soviets into an economic superpower. On the "Today" show, Giffen was contradicted by Roger Robinson, former trade staffer for President Reagan's National Security Council. If the Soviet military becomes the ''main beneficiary'' of perestroika, said Robinson, ''we might just be creating an economically stronger and more dynamic adversary.''

Shultz's diplomats are markedly less pro-trade than Verity's subalterns. A Soviet bloc proposal for an East-West trade-and-aid parley was flatly rejected by Shultz. A similar plan advocated by West German Foreign Minister Hans-Dietrich Genscher is also opposed at State.

But such schemes are not dead. Desperate Soviet need for financial relations with the West combines with Reagan's desire for a new U.S.-Soviet order. Anything can happen, either in unreported meetings at the Soviet Embassy here or in unofficial but officially sanctioned trips to Moscow by James Giffen and his fellow American industrialists.