The major U.S. allies expressed confusion and concern today about the timing of the abortive atempt to rescue American hostages in Tehran and the possibility that it would escalate the crisis in Iran into a military confrontation.

Some of the allied governments, particularly Italy, openly disagreed with the U.S. decision to mount the rescue effort, about which none had been informed in advance.

Officials of several governments in Western Europe referred pointedly to a reluctant allied decision, made under heavy U.S. pressure barely two days before the rescue operation, to support U.S.-sponsored sanctions against Iran in hopes of avoiding military action. The Danish Foreign Ministry said the operation "created a new situation" that would be discussed at this weekend's Common market meeting in Luxembourg.

Most European governments made clear today that they intend to stand by their approval of sanctions and Japan indicated the same.

The Italian government said Italy had expressed its "clear opposition to the recourse to actions of force in any circumstances for the liberation of the hostages."

But other governments, while expressing private alarm, were publicly sympathetic over the mission's failure and the growing U.S. frustration over the hostage situation.

[Japanese Prime Minister Masayoshi Ohira said Saturday in Tokyo that the rescue attempt was "not a military action." Foreign Minister Saburo Okita called it a "humanitarian action."]

British Foreign Secretary Lord Carrington, along with Prime Minister Margaret Thatcher, first heard about the mission's failure on early morning radio broadcasts. He said that Britain had been informed "in confidential diplomatic channels" that such action was being considered some time ago, and added, "We don't want to be too critical."

Carrington said he agreed with President Carter's distinction between a rescue mission and "an act of force or warlike action against Iran," such as a naval blockade or the mining of its harbors.

"If it had been a success, we would all have been applauding," Carrington said. "I'm extremely sorry that it didn't succeed."

Although Thatcher sent a message of support to Carter, expressing her admiration for his decision to make the rescue effort, Carrington tonight called the world situation "very grave" and appealed to the United States to avoid using military force to try to free the hostages.

West German Chancellor Helmut Schmidt made no statement on the aborted rescue mission. But at a closed meeting of the board of his Social Democratic Party, which has been critical of sanctions against Iran, Schmidt advised against reacting publicly until more facts were known, party sources said.

The British response, along with those of Norway and Sweden, were the most sympathetic among the West Eruopean allies. Norwegian Prime Minister Odvar Hordli said he "fully understands the Ameican action" and noted that "no nation can sit idle and let this [siege] continue."

In Sweden, Foreign Minister Ola Uttsten blamed Iran's leaders and urged that the hostages be "immediately and unconditonally released."

Canadian Prime Minister Pierre Trudeau called the operation a "valiant effort" and "expressed the strong hope that these events will have no adverse consequences on the situation of the hostages or on the current round of diplomatic initiatives under way among the Western allies."

In France, the response was somewhat different. The French government said nothing, except to note that no one, including President Valery Giscard d'Estaing, was told anything in advance. All attempts to elicit further public comment met with cold refusal.

In private, however, irritated French officials said that they considered themselves "cuckolded" by Carter, and that they thought the other eight members of the European Economic Community would have the same reaction.

A French official said that Carter had not even waited "a decent interval" since the decision of the Common Market foreign ministers Tuesday to apply a phased sanctions program against Iran.

Nevertheless, evidently sharing Carrington's wish that the operation had succeed and saved everyone the the trouble of sanctions, the official said, "There are still a number of unanswered questions. Why was it called off? Why was a need felt to announce it at all when the Iranians had apparently not noticed antyhing?

"We will say nothing officially, and I'm convinced the others won't either, because no one wants to add to the feeling of frustration that must be felt in the United States."

Another French official offered his pesonal view that Carter's action, after presenting his appeal for European support of sanctions as an attempt to avert military action, cannot but have consequences upon how things are viewed on both sides of the Atlantic."

In a front-page editorial the afternoon newspaper Le Monde, widely regarded as the voice of the French establishment, was far more direct, calling the operation "the poor man's Bay of Pigs," a reference to President Kennedy's unsuccessful attempt to overthrow Cuba's Fidal Castro.

While the editorial said the U.S. public might pardon the operation as a legitimate effort to save Americans, "abroad, however, the crebidility of the United States will suffer again. The image of a hesitant and unlucky president will be reinforced.

"What is one to think of the effectiveness of a military apparatus upon which the security of half the planet depends if it, is incapable of landing two planes in a desert even before the enemy has intervened? What remains of the Carter Doctrine that claims to protect Western interests in the whole region of the Gulf?"

European ambassadors are scheduled to return to Tehran this weekend to inform Iranian President Abol Hassan Bani-sadr that sanctions would be imposed May 17 unless there is "decisive progress toward release of the hostages." But this is being done with even less enthusiasm or hope of success than before today's events.

Both government and opposition spokesman in several countries said the aborted rescue operation had greatly increased the possibility of military escalation.

Australian Foreign Minister Andrew Peacock said that "I trust that in the day ahead there will be a great deal of restraint shown by all parties."

In Britain, the opposition Labor Party's foreign affairs spokesman, Peter Shore, said, "The world will be holding its breath this weekend. It is important that the governments of the West make plain to the United States that warlike measures will not work" to release the hostages and will threaten world peace.

There were indications of growing political opposition to legislation necessary to enable Britain to impose sanctions against Iran. Prominent leftist Labor members of Parliament introduced a resolution calling on the government to inform Carter that "unless the U.S. government gives an assurance" that no more military action will be taken, "the British government will withhold cooperation on economic sanctions."