Lord Killanin of Ireland, who is simply "Michael" to those who know the exuberant and approachable man behind the title, leaned back on the sofa of his hotel suite, puffing thoughtfully on his pipe, contemplating what he has called "the most serious challenge to confront the Olympic Games."

The president of the International Olympic Committee looked over his half-glasses, his jowly face propped up by his right arm. He spoke in a grandfatherly sort of way -- concerned, understanding, yet firm and confident in his strict point of view.

As he discussed the circumstances that may lead to the nonparticipation of the United States and like-minded nations in this summer's Olympic Games in Moscow, it was evident that there are conflicts between his personal political preferences and his deeply felt responsibilities as the chief trustee of the Olympics, which the IOC owns and oversees.

Killanin, a self-described "democrat, with a little d, and liberal, with a little l," was put in the decidedly uncomfortable position of declaring last week that the Games would go on as scheduled in Moscow, despite the Soviet invasion of Afghanistan, which intimates say he personally regards as reprehensible.

"I think it is unfortunate that President Carter, followed by Mrs. Thatcher in Britain, made this decision (to use the Olympics to repudiate the Soviets) without consultation with the National Olympic Committees or sporting bodies in their countries to see exactly what the setup is, and how the Games are organized," he said.

"I also think it is unfortunate that a document should have been issued in the Soviet Union -- not by the Moscow Olympic Organizing Committee, but by the party and the Soviet government, which are hard to separate -- which claims that Moscow was awarded the Games because we agreed with their foreign policy and system of government, which is absolutely untrue.

"We awarded the Games to Moscow because, since 1952, when the Soviet Union came back into the Olympic Games at Helsinki, they have contributed greatly to sport. That alone was our consideration. It was a sporting decision, not a political one.

"At the time," Killanin went on, recalling that the agreement allocating the 1980 Summer Games to Moscow was signed on Oct. 23, 1974, "99 percent of the world welcomed the decision as opening a door. Now certain of the big democracies are trying to close that door . . . . When the Games were awarded, we were in what was known as a period of detente, and now suddenly we find that the hawks are back again."

Those close to him say that Killanin who was so distressed by the propagandistic "Nazi Olympics" at Berlin in 1936 that he temporarly abandoned his career on Fleet Street and joined the British Army, personally wishes there were some way the IOC could hold this summer's Olympics someplace other than Moscow.

He honestly believes it is technically impossible to move the Games, and would be legally and morally wrong to do so because the Moscow organizers have not broken any of the terms of the contract they signed in 1974.

Killanin, whose grandfather was Chief Justice of Ireland and was bestowed the title Killanin now holds by Queen Victoria, rejects the legal argument presented by the U.S. Olypmpic Committee, which petitioned the IOC, at President Carter's request, to move postpone, or cancel the Moscow Games.

The USOC contended that Soviet aggression violated the "fundamental principles" of the IOC Charter, which state that the Olympic Games are to be celebrated every four years in a spirit of peace, nondiscrimination and international goodwill.

"Unfortunately, at the time of all the Games of my Olympic life since the war, there have been conflicts going on," said Killinin.

"I don't want to be provocative, but the United States was fighting in Cambodia at the time the current Winter Games were allocated to Lake Placid. We've had wars in North Africa; the Middle East, the Far East, and it is not for us to judge which countries were invited in and which invaded.

"The ideal would be -- and I remember my predecessor, Avery Brundage sending out messages to this effect -- that we have a truce for the time of the Games, as happened in Greece for the ancient Olympics. But I'm afraid no one heeds us on this," said Killinin, who sees himself as a sports administrator and not a politician.

"My great regret is that we are endeavoring to promote mutual understanding through sport, to be a grounds of international friendship and cooperation, and suddenly the Olympic Games are being used as a political weapon in an ideological struggle," he said.

It was Killanin -- educated at Eton and the Sorbonne; and who traveled widely as a reporter covering wars and politics, crime and royal abdications, and sports for a time -- who wrote the final draft of the statement issued by the IOC a week ago, rejecting the USOC proposal but at the same time chiding the Soviet Union.

The statement urged Soviet Olympic officials "to inform the highest authorities of their government of the circumstances which have created these difficulties," and encouraged the major powers to "resolve their differences . . . so that the Games of the 22nd Olympiad can be celebrated in the right atmosphere."

Killanin suggested at the time that observers "read into this statement as I, as an old reporter, always read into statements that are carefully worded." iNow, sitting on his sofa, he added: "I would read quite a lot into it, actually. Quite a lot indeed."

Clearly, he thinks the IOC has done what it could, and now it is up to the Soviet government to withdraw its troops from Afghanistan and make initiatives to defrost the Cold War before the May 24 entry deadline for the games if it wants the U.S. and its allies to participate in Moscow.

"I think time is important to everybody, and this is what I was endeavoring to do: get the maximum amount of time for everyone, until we see what happens," said Killanin. "Neither you nor I know what's going to happen in the world. It changes day by day. That is why it is so important to keep one's options open."

The USOC and the White House wanted the IOC to defer action on the U.S. proposal, to put pressure on the Soviets to get out of Afghanistan by throwing the Moscow Games into limbo until they did. Killanin did not think there were grounds for doing this, and 72 other IOC members agreed.

"I think we are locked in contractually," Killanin said, "but our statement was very carefully worded to point out our problems, which the Moscow Organizing Committee must appreciate. Every word was very carefully weighed up. We did draw their attention very firmly to the fact that the Games were not given to them for political reasons.

"If we started saying," 'Do we like the type of government you have?', we could never agree on a site that would satisfy all 143 of our National Olympic Committees. It's not our business, and it's not our place to judge. o

"I don't, for instance, particularly like the regime in the Argentine," he continued, "but I saw no reason that the soccer World Cup shouldn't be held there. I think it's the same thing with the Olympics in Moscow. . . What the Soviets have done in Afghanistan doesn't change the circumstances under which the Games were awarded."

Killanin appreciates the viewpoint, apparently now espoused by the Carter administration and a significant portion of the American public, that Soviet aggression has made Moscow an unsuitable site for Games dedicated to peace, no matter what placating gestures the Soviet government might make between now and May 24.

"It is not compulsory for any National Olympic Committee to attend the Games. That is their decision, to be made in good conscience," he said, pointing out that Ireland chose to boycott the 1936 Olympics in Berlin.

"I hope the majority will attend, but this is their decision, and they may decide not to go for any number of reasons. No federation and no individuals need go if they don't want to."

Killanin has said that the IOC might reconsider moving, postponing or canceling the Moscow Games if world conditions change, or if a substantial number of National Olympic Committees decide -- on their own or because of orders or more subtle prompting from their respective governments -- to decline invitations to Moscow.

"I think that is unlikely," he said."I would like the Games to go ahead, but a lot will depend, I think on what happens in Western Europe."

The Carter administration, in an effort to rally international support for nonparticipation, is urging the USOC to promptly and irrevocably decline its invitation to Moscow as soon as the Feb. 20 deadline President Carter set for "full withdrawal" of Soviet troops from Afghanistan passes.

Asked if this undercuts his "play for time" strategy, Killanin simply shrugged and said, with a trace of resignation, "I don't run the White House or the State Department."

One of the great disadvantages Killanin has found in his eight-year tenure as IOC president, which ends this year, is that he often is expected to act as a political force, but he doesn't have the tools of government at his behest.

The IOC, he has remarked in the past, has no armed forces. It cannot order governments around. It has only its charter, setting out the goals of the Olympic movement and the rules by which the Olympic Games, which it owns, must be organized. It is this charter that the IOC is pledged to uphold "in the manner of a boad of trustees."

"It is not my place to inject my personal political opinions or feelings," said Killanin. "The Soviets have not missed a step in living up the terms of their agreement with the IOC. The circumstances in which Moscow was awarded the Games have not changed." The IOC has neither the power, nor the responsibility, he was saying in effect, to punish them.