Canada's government, basking in unaccustomed international glory, today belittled Iranian threats to get even for the smuggling of six American diplomats out of Iran.

External Affairs Minister Flora MacDonald, in a Toronto television interview, noted that Canada's relations with Iran have already "dwindled almost to nothing" since American hostages were seized in Tehran 12 weeks ago.

"I didn't expect Mr. Ghotbzadeh to come out and praise us," she said, referring to a threat by Iranian Foreign Minister Sadegh Ghotbzadeh to "make Canada pay" for spiriting the Americans out of Tehran.

Although the U.S. government announed that the six Americans had arrived at Dover (Del.) Air Force Base, Canada continued to conceal their whereabouts. The six escaped with Canadian passports early Monday morning after hiding for three months in Canadian Embassy residences.

Details were pieced together in interviews with Canadian officials who coordinated the tense three-month diplomatic effort in Tehran, Ottawa and Washington.

Although the escape had been planned for two weeks, the story only surfaced yesterday with reports that the six Americans -- all believed to be in good health -- and four remaining Canadian diplomats left Tehran by airplane for Europe.

More than 12 weeks earlier, Islamic militants stormed the U.S. Embassy in Tehran and rounded up the American diplomatic personnel inside for the beginning of the protracted hostage crisis.

The six Americans, fleeing out the embassy's back door, spent the next few days living with friends in other diplomatic missions in Tehran and making telephone contact with Canadian Ambasador Kenneth Taylor.

Taylor transmitted the Americans' request for sanctuary in the first of dozens of coded telex messages to Ottawa. After a brief debate within the government, MacDonald received approval from Prime Minister Joe Clark to take in the Americans.

Arriving at the Canadian Embassy shortly after Taylor received the go-ahead, the six Americans were separted into two groups -- the two married couples remaining together.One group was driven to Canada's official residence in north Tehran, while the other pari was taken to the nearby home of a Canadian diplomat.

During their stay, the Americans ventured forth for walks within the affluent neighborhood. Meeting together, they spent much of their time playing cards in the large official Canadian residence.

In a series of messages sent from Tehran to Ottawa and then to the Canadian Embassy in Washington, the six Americans were able to keep their families informed of their welfare. In December, Christmas greetings were exchanged.

A special task force at the External Affairs Ministry kept in close contact with Taylor, passing along his reports to the U.S. Embassy in Ottawa and to the State Department.

Although a few European diplomats were told that the Canadians were harboring the group, which became known as "the American guests," the international hideaway was the bestkept secret in gossipy Tehran.

Taylor, 45, a trade expert placed in charge of the Canadian Embassy in August 1977, was known as one of the most generous hosts in Tehran, frequently inviting journalists and other guests to his home for dinner and drinks in the alcohol-free Islamic state.

For the first several weeks, Canadian officials planned to keep the Americans in hiding until the U.S. Embassy crisis blew over. But as the embassy occupation dragged on and the fear of being caught with the Americans increased, their views changed.

Plans to smuggle out the Americans began to form about two weeks ago, a time Taylor considered favorable because the Iranians were distracted by the Soviet military invasion of newighboring Afhghanistan and by their first presidential election.

Several possibilities were considered in Ottawa, including disguising the stowaways as Americans business representatives or giving them passports from a third nation. Finally officials decided to give them Canadian passports to ease their way through customs at Tehran's Mehrabad Airport.

Issuing the passports to non-Canadian citizens required a special Cabinet order, given in private Jan. 4. Once approval was given in Ottawa, the Canadians were given help by U.S. intelligence agencies in producing Iranian visas.

Several trial runs were staged by Canadian Embassy officials, who used falsified documents at the airport to make sure they would pass without notice.

The Americans left Tehran's airport together early Monday morning, flying to West Germany. Taylor and three other Canadian diplomatic officials left about 4 p.m. the same day and landed in Copenhagen.

Soon after the diplomats left, a message was sent from Tehran presumably from another embassy, confirming that the mission had ended successfully.

In Ottawa, the handful of Canadian officials who had participated in the delicate mission gathered in the External Affairs Ministry for a bottle of champagne.

Canadian officials were still enjoying themselves today as lavish praise streamed in from their compatriots and Americans.

For Prime Minister Clark, whose Conservative government fell last month amid complaints that he was too weak in his support for the American position in Iran, the "Canadian caper" came as a welcome help in his campaign for reelection Feb. 18.

Although he has avoided taking credit for the mission, his government was praised in newspaper editorials. Canadians interviewed today expressed great pride in the venture.

"It's great that Canada stood up for America," said Tony Finn, 26, an Ottawa cab driver. "Finally Canada did something to help the States. It's nice to be strong neighbor."

Former prime minister Pierre Trudeau, the Liberal Party leader who opposes Clark in the upcoming federal election, begrudgingly complimented his rival's government, even though he has attacked Clark persistently in past weeks for not giving strong enough support to the United States.

As the opposition leader, Trudeau was consulted several times in recent weeks about Canada's mission in Tehran. According to one report, Clark walked across the floor of the House of Commons during one of Truedeu's outbursts in mid-November and reminded the former prime minister of the Iranian venture.

Today, Clark's office was flooded with hundreds of appreciative telegrams and telephone calls from Americans. A man from Port Chester, N.Y. said in a telegram, "I think some Americans must look to Canadians for the type of leadership that Americans should have in this country."

In a radio interview today, Clark expressed little concern about Iranian threats of retaliation. He said his government has not taken a special security precautions in Canadian embassies abroad.

Other Canadian officials also brushed off Iranian threats, noting that their nation has little business left with Iran. Although Canada imported 10 percent of its crude oil from Iran, that business arrangement ended after the American hostages were seized.

Before the February revolution in Iran, Canada had exports of about $150 million a year to Iran, including large shipments of barley. In the first 11 months of 1979, however, exports dropped to just $24 million.