Secretary of State Cyrus R. Vance ended his European mission yesterday, with U.S. officials saying he found general agreement about the seriousness of the Afghanistan crisis but continuing diferences over the best way to respond to Soviet moves in Southwest Asia.

On the surface, Vance's efforts to forge a more unified U.S.-West European response to the Soviet appeared to have ended inconclusively. His talks with European leaders failed to produce any further mass movement toward an Olympic boycott or other specific steps to deter aggressive Soviet moves like the invasion of Afghanistan.

However, a senior U.S. official aboard Vance's plane said the secretary returned home personally encouraged that he had dispelled much of the confusion and uncertainly with which the Europeans had viewed the profound changes taking place in U.S. policy since the Afghanistan crisis began.

Vance, the official said, felt his face-to-face talks with the foreign ministers of America's four principal European allies had helped to shift the dialogue withing the Atlantic alliance away from complaints about a lack of U.S. consultation with its partners and fears that the United States and Moscow are on a confrontation course that could produce a new cold war.

Instead, the official continued, Vance believes there now is a much greater consensus among the allies about the long-range, global implications of the Afghanistan situation. While conceding that a great many disputes over tactical responses must still be resolved, the official asserted that this consensus has provided the North Atlantic Treaty Organization partners with a framework for moving closer to a collective strategy in the weeks ahead.

Specifically, the official said, Vance and the foreign ministers of West Germany, Britain, France and Italy agreed that any effective strategy must take into account these factors:

Strengthening NATO defense forces and reducing the dependence of the western industrial powers on oil supplies from the politically volatile Persian Gulf region.

Making the Soviet Union pay for its aggression in Afghanistan and blocking Soviet efforts to lessen the penalties by driving a wedge between the allies.

Maintaining pressure on the Soviet Union to withdraw from Afghanistan by evolving and holding out plans for negotiating a political solution to the crisis.

Managing East-West relations through the duration of the crisis in ways that will preserve some semblance of the decade-old movement toward detente and that will permit a renewal of improved relations once the Afghanistan situation is resolved.

Strengthening the western position in Southwest Asia and the Middle East through establishment of a greater allied military presence there and through closer economic and military assistance ties to the countries of the region.

In sorting out these elements, U.S. officials admitted, important differences remain among the allies about which are the most important and require the greatest emphasis.

Although the United States has denied repeatedly that it is being vindictive toward the Soviets, there is a definite feeling in Europe that the Carter administration has put too much stress on punitive moves like trying to organize a boycott of the Moscow Olympic Summer Games and denying the Soviets grain and high-technology imports from the West.

France, in particular, has been outspoken in opposing this approach and has argued instead for putting the main emphasis on trying to negotiate a Soviet withdrawal from Afghanistan. West Germany and Italy have taken a position more in the middle, although like France they have a strong vested interest in continuing detente. Britain, which started out with attitudes close to the United States, lately has also been moving toward the middle ground.

This week, these four countries and other members of the European Economic Community joined in proposing that Afghanistan be transformed into a neutral state under international guarantees. The possibility that this plan may have struck a responsive chord in Moscow was raised by Soviet President Leonid I. Brezhnev's call yesterday for guarantees of noninterference in Afghanistan by other nations.

The initial U.S. official response was wary, with State Department officials saying it was too early to tell whether Brezhnev's speech was a signal to explore negotiations on neutralizing Afghanistan or simply an attempt to exploit the differences among the United States and its European allies.

However, the senior official said Vance had told his European counterparts that the United States favors pursuing any track that might lead to an acceptable negotiated solution. Although the United States is known to feel that the neutralization idea is too vague at this point to raise hopes too high, the official said Vance had gone out of his way to encourage its future pursuit.

Regarding other tactical questions, U.S. sources said the area of greatest disagreement involved sanctions against the Soviets. France, predictably, reacted most coolly to that, and the others also expressed some reservations about escalating trade sanctions.