President Reagan has spent a week in Europe promoting his vision of democracy and private enterprise, an effort that was supposed to culminate today with an inspiring address to the European Parliament commemorating the 40th anniversary of the allied defeat of Nazi Germany.

National Security Adviser Robert C. McFarlane, who briefed reporters the day before, said the speech would feature "a very soft sell" of the president's "ideas for resolution of the problems with the Soviet Union."

But for Reagan, who prides himself on his persuasive skills, it has been a week in which he has encountered unusual difficulty in making a sale.

The president's ragged performance today, caused in part by a breakdown of his teleprompter and partly by leftist hecklers among the parliamentary delegates, deepened a week-long impression that Reagan's journey to Europe is a mission gone awry.

At the economic summit in Bonn, Reagan found all of his European counterparts opposed to U.S. economic sanctions against Nicaragua, and most of them skeptical of his antimissile defense plan popularly known as "Star Wars." France rejected almost everything that the United States proposed in either economic or foreign affairs.

The day after the summit ended, Reagan tried to extricate himself from the self-inflicted damage caused by his decision to lay a wreath at a German military cemetery where 49 members of the Nazi SS are buried. Reagan partially succeeded with two powerful speeches, but Jewish leaders refused to participate in the ceremony at the Bergen-Belsen concentration camp site and the event was further marred when more than 30 Jewish protesters, some of them the children of Holocaust survivors, were hauled away by West German police outside the camp gates.

Yesterday, Reagan held talks with Spanish Prime Minister Felipe Gonzalez that both leaders described as relatively successful. However, these talks also failed to produce the favorable television publicity that is always a central purpose of Reagan's journeys abroad. Network coverage of Reagan's visit to Madrid yesterday contrasted the friendly ceremony of the state dinner that Reagan was attending with pictures of anti-Reagan demonstrators being charged and bloodied by police near the U.S. Embassy.

In addition to these conspicuous embarrassments, Reagan's effectiveness also has been hampered by a series of minor mishaps that conflicted with the White House's reputation for smoothly choreographing events.

When reporters asked why Reagan had made no mention of the Soviet role in World War II in his speech today, White House officials produced a letter that they said Reagan had sent yesterday to Soviet leader Mikhail Gorbachev. But Reagan seemed unaware of the letter when he was asked a question about it by a reporter.

White House officials also may have slipped up in failing to alert reporters to today's protest, which they now claim was anticipated. McFarlane held a briefing last night that lasted longer than the president's speech today, but did not mention any expected heckling.

While Reagan has been less successful than usual in achieving the rhetorical triumphs that have been a feature of his presidency, his speeches have placed him squarely in the mainstream of post-World War II presidents in appealing to the traditional values that grew out of the wartime alliance.

Throughout the week Reagan has quoted from former U.S. presidents Franklin D. Roosevelt, Harry S Truman, Dwight D. Eisenhower and John F. Kennedy in appealing for U.S.-European cooperation. His speech here today ruled out any U.S. goal of achieving nuclear superiority, once a Reagan goal.

He also said that "the United States does not seek to undermine or change the Soviet system nor to impinge upon the security of the Soviet system." This was in marked contrast to the emphasis of Reagan statements on his 1982 European trip, when he talked about the eventual collapse of the Soviet system.

It was phrases like this that brought McFarlane into conflict with White House communications director Patrick J. Buchanan, who reportedly favored a harder line toward the Soviets.

A well-informed White House official said that McFarlane wanted to go beyond deploring Soviet conduct to make a number of practical suggestions for improving U.S-Soviet relations, as Reagan did today.

"Reagan is a conservative, and this was a dispute between conservatives," said the official. "But it was clearly a victory for McFarlane and Secretary of State George P. Shultz, who wanted the speech to take a constructive approach."

While Reagan today praised European values and said the united states is committed "to the re-creation of a larger and more genuinely European Europe," he has spent much of the week suggesting that the basic elements of his domestic program -- especially reducing government regulations and cutting taxes -- should be adopted even by socialist-minded European goverments.

"We believe that a rising tide lifts all Europeans," quipped a White House official earlier this week in a paraphrase of Kennedy's assertion that "a rising tide lifts all boats."

That quotation, sometimes cited by Reagan, was used by Kennedy to argue for stimulative tax cuts.

"The historical record is clear," Reagan argued in a speech to Spanish community leaders yesterday. "Tax cuts work. Germany lifted itself out of the ashes of World War II in the late 1940s when Ludwig Erhard reduced that country's tax rates. Starting in 1950, over 20 years of tax cutting did the same for the Japanese, catapulting them out of underdevelopment and into the front ranks of world economic power."

Reagan made a similar appeal Monday in a rousing speech to West German youth, one of the few events of the week that went without a hitch.