Prince Norodom Sihanouk traveled in less than a week from the obscurity of house arrest in Cambodia to the limelight of center stage at the United Nations, another startling turnabout in the uncommon career of this durable performer of the political arts.

Sihanouk already had been shorn of his powers for more than a year when he told the Khmer Rouge rulers in 1976 that he no longer wanted to play the role of their chief of state -- a stand that proved to be the first step on the trip that has landed him at the Security Council.

"I did not want to be held responsible for their crimes," Sihanouk explained over dinner last week. "No, I didn't tell them that. I said that I was getting old and losing my intelligence. If I had said it the first way -- boom!" the prince said, pointing his index finger to his temple.

For the next three years the prince lived in isolation with his wife, Monique, and their family. "I did fear execution. Every day I had to think about it, because I really did not know what was the regime of Pol Pot."

While the Cambodian Communists were launching their harsh experiment of total social relocation, regimented life and constant labor, the prince said he listened to his radio, read and slept at most two or three hours a night.

Only Khieu Samphan, the man who replaced Sihanouk as figurehead leader of Cambodia, passed the armed guards and locked gates to visit Sihanouk at the royal palace along the Phnom Penh riverfront. In 1976 Khieu Samphan came three or four times. In 1977 he did not come at all.

Yet today, Sihanouk is representing his jailers of three years at the United Nations. At Security Council sessions here he calls them the worst violators of human rights in the world, and in the same breath says they are the only legal government of Cambodia.

"My life is one of ironies," the prince said at dinner. "It has not been pleasant."

Every direction he turns, Sihanouk and his nation are faced with allies who were once enemies, enemies who were once allies. The United States supported the generals who overthrew Sihanouk in 1970, but now, every day, he embraces U.S. Ambassador Andrew Young on the floor of the Secutrity Council, looking to him for support.

The Vietnamese Communists, with whom he was allied during the Indochina war after 1970, now are his foremost enemies. It is the task of the prince to search through this maze to find a solution to "restore independence to Cambodia" and convince the Vietnamese through the U.N. forum that they must withdraw their troops from Cambodia.

It is a situation that, as one diplomat says, "crys out for Sihanouk."

Somehow the prince seems to enjoy this formidable task.

"I could negotiate a settlement," the prince boasted at the dinner party. "I know the Vietnamese well. If we do not find a solution soon, they will be in Cambodia forever."

If the Vietnamese would promise to withdraw their troops, the prince said, he would promise to sell them rice at a low price, promote relations with all nations, including the Soviet Union, and ensure that Cambodia would be truly nonaligned.

What about the often cited hatred of the Cambodians for the Vietnamese, he was asked. Would the Cambodians agree to such a settlement? "We Cambodians fear the Vietnamese -- fear, not hate. So many Cambodian generals had Vietnamese mistresses -- how could we hate the Vietnamese when we like the pretty Vietnamese girls so much?"

Sihanouk has often used hyperbole in order to make his point. He avoids bureaucratic jargon. It is offensive to many regular diplomats, but it has been highly effective.

Since his ascension to the Cambodian throne in 1941 at the age of 18, Sihanouk has succeeded with this diplomacy of "brutal truths."

In 1953 he secured independence for Cambodia from the French without resorting to battle. He kept Cambodia out of the Indochina war until 1970 by becoming a larger-than-life statesman, chastising whichever power he felt was threatening him and becoming a major figure in the nonaligned movement. But in 1970 he was overthrown by U.S.-backed generals and he supported the Communist Khmer Rouge, who defeated the generals' army in 1975.

"There are only two men responsible for the tragedly in Cambodia today: Mr. Nixon and Dr. Kissinger," the prince said.

Without the support the United States gave him, Gen. Lon Nol could not have remained in power, the prince said. He called the annual $750 million American assistance to Lon Nol "involuntary aid to the Khmer Rouge," because the Cambodian people were forced to take the side of the Communists against Lon Nol.

The prince made these statements within earshot of two Foreign Ministry officials with whom he is working and living at the Waldorf Astoria. He said clearly what he felt about their government: "I heard them say over the radio that for 2,000 years the people of Cambodia starved because of Sihanouk and his ancestors... I head them say Ieng Sary was the greatest of diplomats and everyone applauded his speeches at the United Nations."

The prince then bowed his head over an imaginary radio: "I apologize to them, for Sihanouk and his ancestors... but people did not starve under Sihanouk and the country was beautiful, very beautiful."

In 1978, after the first intense border clashes between Cambodia and Vietnam, Sihanouk and Monique were brought out to the provinces by the Pol Pot government to be seen by the peasants; once each month from January through April, and again in September.

"The people still loved my husband," Monique said. "The women -- you know Cambodian women -- they cried when they saw him and one woman, she ran after the car calling for the prince."

The last visit was to Battambang just before the Vietnamese invasion. On Jan. 5, the prince and princess were told they were to go on their mission to the United Nations. Monique said that the only thought in her mind when they left Phnom Penh with their family was "freedom."

On Friday, in reply to a speech against him by the Cuban ambassador, Sihanouk said that, yes, the Pol Pot government was the worst violator of human rights in the world.

But the admission was used to make a point against Cuba and the Soviet Union. "Did not Castro kill thousands if not tens of thousands of supporters of Batista?" the prince said, adding that the dissidents in Prague and Moscow tell stories about human rights in Czechoslovakia and the Soviet Union, the chief ally of Vietnam.

"They are to be put into the same category as Pol Pot and Ieng Sary," he said, looking at the Soviet ambassador seated across from him at the Security Council.

Admission of human rights violations in the country Sihanouk represents is only one of the contradictions the prince believes are rational. He has said repeatedly that he represents the Pol Pot government because "it is the legal government of Cambodia -- history would not treat me as a patriot if I went against my government. Then I would be a traitor."

Yet the prince doubts that the Pol Pot government will succeed in overthrowing the new Cambodian rulers and driving our their Vietnamese backers.

"They say they are stronger than ever," Sihanouk said, pointing in the direction of his colleagues who were Foreign Ministry officials of the Pol Pot government., "They say they will fight to the end and they will win, but they live in illusion -- like Goebbels in the last months of the Hitler government."

This was one of the countless comparisons Sihanouk has made between the situation of Cambodia now and that of Europe in World War II. Sihanouk inevitably sees himself as the Charles de Gaulle of the Indochina conflict.

In his reply to the Cubans, Sihanouk contended that he was independent -- far more independent than Cuba of its Soviet allies -- and not a mouthpiece of Pikeing, as the Cubans charge.

"Chairman Mao Tse-tung liked to tell me I was an adorable prince," Sihanouk said, "and in his adoration he wanted me to convert to communism... But to me, communism is like mathematics, physics and chemistry; I don't know a thing about it."

After the speech, U.S. Ambassador Andrew Young said he thought Sihanouk is "an amazing guy."

"The man has maintained his integrity and courage in the face of real difficulties," Young said. "Somehow he has survivied without seeming to have compreomised himself."