The soaring value of the dollar, now worth up to 50 percent more than a couple of years ago, is resurrecting cries of Yankee economic imperialism in Europe.

When the Carter administration let the greenback drop, Europeans drew snide analogies between the sick dollar and a feeble government in Washington. Now the complaint is that the dollar is dangerously overvalued and the failure to remedy the situation is symptomatic of President Reagan's arrogant disregard for the plight of European allies.

The only people elated by the turnabout seem to be American tourists, who are expected to flock to Europe this summer in record numbers. For the first time in recent memory, a frugal traveler can swill beers in Belgian cafes for 50 cents a glass or eat steak dinners for less than $5. The dollar is now worth about 2.5 West German marks or 7.5 francs, while the pound costs $1.58.

But European governments find little solace in the prospect of a surge of tourist revenues. In its weaker days, the dollar made life difficult for European exporters, who were undercut by their American competitors. Today, Europeans find that they must pay dearly for such dollar-priced imports as oil and other critical raw materials, thus negating benefits that they might derive from greater exports to the United States--or more spending by American travelers.

Given the fervent desire among European leaders to see Saturday's Williamsburg summit succeed in a troubled year for the Atlantic Alliance, this has boxed European leaders in a dilemma, pitting diplomatic etiquette against the desire for drastic action to revive the world economy.

Europe's five summit participants concur that Washington must be coaxed into cutting its budget deficit, which is blamed for the high interest rates. These, in turn, are blamed for Europe's lingering recession. The continuing rise in value of the dollar is seen as a major symptom.

President Reagan's declared opposition to increased taxes, which received wide publicity here, has focused attention once again on how to reduce U.S. defense spending.

A top minister in the Bonn government suggested last week that since "a signal of resolve" of U.S. determination to shore up western defenses has been drilled into the Kremlin, the Reagan administration might safely consider lower interest rates to stimulate the world economy as a new security priority.

Senior European officials here in the Belgian capital and in Bonn admit that such discreet calls to bring Reagan around to their views on the dangers of high interest rates could be misconstrued as meddling in the U.S. policy debates.

"We know it's not easy for the U.S. to find its way out of these big budget deficits," said a high-ranking European Community official. "You have already cut social programs and need to pay for defense needs. But something must be done."

ADMINISTRATION RESENTMENTS of such pressure, it is feared, could quickly evolve into what European Community "sherpas," or those who planned the Williamsburg agenda, have dubbed the "nasty summit scenario."

They speculate that a harsh sermon, for example, by French President Francois Mitterrand or Italian Prime Minister Amintore Fanfani on the problems posed by high interest rates could elicit an American retort about "intolerable" inflation in those two countries.

Or the United States could lash back with tough demands to curtail East-West trade, a subject that the Europeans were relieved to find confined to a minor spot on the agenda.

"Happily, it appears in everyone's interest to have a nice summit, not a nasty one," explained a European Community official. "We don't like you Americans to give us lessons, and I'm sure you don't want us to lecture you."

"The risk is that each leader will want to prove to people back home that he played a strong, assertive role at the summit," he continued. "The question is whether they will all behave with statesmenlike restraint."

An amalgam of personal considerations seems to dictate an amicable meeting. British Prime Minister Margaret Thatcher and Fanfani face elections next month. West German Chancellor Helmut Kohl wants a successful summit behind him when he heads for talks in Moscow in early July. And Reagan, as host, has no desire to spoil his own show.

Only Mitterrand, who brooded to journalists the other day that he foresaw no great promise in the summit and might just as well stay home, may perceive political dividends in raising a dissenting voice as the only Socialist leader at Williamsburg.

THE SIX-PAGE "thematic paper" now being passed around the capitals will serve as the basis for a final communique, and in the words of one European "sherpa," it "offers something for everyone."

"We sure came a long way," sighed a European Community aide active in planning the summit. "Our first impression was one of utter confusion."

In the early stages, the Europeans were taken aback by the Reagan administration's proposal for a summit that examined East-West trade, monetary issues and ways to combat protectionism.

After several prickly sessions, the "sherpas" reached a consensus on a general paper that met the concerns of all participants. The climate was also enhanced by robust signs of economic recovery in the United States and Japan.

"But nobody really knows what importance Ronald Reagan attaches to this paper, and what he will really do," a community official said. "It's still up in the air."