He attended the same law school as Philippine President Ferdinand E. Marcos, was a member of the same fraternity as Marcos, and has known Marcos' wife Imelda intimately since childhood. But when he travels from Cambridge to Chicago Monday to address the Council on Foreign Relations, he will not defend Marcos' policy or ask for American support for the military regime. For events have made Benigo S. Aquino Jr. Marcos' most feared and hated enemy, one of the first jailed when the dictator imposed, in 1972, the martial law that still envelops the country

Aquino, 48, probably would have won the 1973 election in the Philippines--had it been held. Instead, he continued to languish in jail, until Marcos finally let him out of the country this summer to undergo a triple bypass operation in the United States. He has now landed at the Center for International Affairs (CFIA), where he has spent time convalescing, pondering his country's future and "meeting all the people who wrote the books" he read during his lengthy incarceration.

Last weekend, on the eve of the eighth anniversary of martial law, Marcos appeared on national television in the Philippines and accused Aquino of colluding with the U.S. to undermine his regime and of sponsoring the wave of urban terrorism which has stricken the country and threatens to topple the dictatorship. The next day, however, Marcos made a public offer asking Aquino to return home and accept a "high government post," in the hope of restoring order to a nation in disarray.

After seven years and eight months in prison, Aquino has no small sense of irony. He knows Marcos could not afford to let him die of a heart attack in jail without creating a martyr and risking the collapse of the regime. He knows he alone can help Marcos stem the ever-swelling tide of revolution in a country that, as he says, "has been under martial law for far too long." Although he bounds about the placid office in Coolidge Hall with energy remarkable for someone just weeks removed from major coronary surgery, he knows the danger to his health and to his life if he returns. He also realizes he cannot stay away too long. "I don't want to regret ten years from now--when it's too late--that I decided to play it safe," he says.

Animated and overflowing with nervous tension, Aquino continues. "I don't want my country to go the way of Iran and Nicaragua. If Marcos falls and brings all the institutions down with him, we will have anarchy. It will take ten, maybe 15 years to rebuild. My friends and supporters back home will say, 'Marcos is going, why don't you move in for the kill? But we have to be able to pick up the pieces, to maintain a semblance of order."

Aquino draws a sordid picture of the Philippines, one that seems vaguely familiar. He says that the story of Marcos' slipping hold on power can be applied roughly to the 14 military dictatorships that have fallen in the last year. "Look, after eight years of martial law, Marcos is losing his grip on the levers of control. If you remove political rights of the people and bring in economic prosperity, you can stave off opposition. But when the economic situation deteriorates, the levers get beyond control."

He lists four external factors that have contributed to the explosive situation in the Philippines, where 20,000 students have been reported protesting and where the incidence of terrorist bombings and guerilla campaigns is increasing daily. "The rise in OPEC oil prices--$180 million before martial law, $12.2 billion now--worldwide inflation, international recession, and an unmanageable national debt--$2 billion in 1972, $11.2 billion now-- have all made Marcos' regime untenable," he says.

But, Aquino insists, "Marcos has no one to blame for the mess but himself. I keep telling him to negotiate now, while he's still comparatively strong, and give freedom back to the Philippines while he can still dictate terms. I tell him not to wait until it's too late. But that's the tragedy of dictators--Somoza, Pol Pot, the Shah--they all wait until it's too late."

If he receives a formal invitation to return home--he speculates the public offer was merely a "trial balloon"--Aquino will give Marcos four "minimum demands." His conditions are restoration of freedom of the press, freedom of assembly for students, labor's right to strike and "honest, clean, orderly elections."

Although he can safely speculate from abroad, Aquino is conscious of the dangers of remaining here too long. As Peter Stanley, dean of Carleton College and a leading expert on the Philippines, says, "If Aquino stays at Harvard, he would either have to mount a successful operation in exile--which has never been done--or in effect rule himself out as a successor to Marcos."

Stanley adds that the decision to spend time the CfIA represents a "poignant choice" for Aquino. "While he increases his chances for personal safety, health and freedom, he risks losing the immediate contact which he needs to gain power," Stanley explains. He says that he believes Marcos may have struck a deal with Aquino, hoping the dissident's release would have a moderating influence among opposition groups in the U.S. and in the Philippines. If anything, though, Marcos has miscalculated: Aquino has embarked on a full speaking tour to present himself as a reasonable alternative in the U.S., and while urban guerilla forces in the Philippines deny that Aquino is masterminding their bombing campaign, they have proclaimed him a rallying point for the Filipino people.

U.S. officials, however, do not readily concede that the fall of Marcos' regime coupled with Aquino's ascendancy is in America's best interests. "Aquino has an interest in being here and saying, 'The economy is going to the dogs, and opposition is uniting, and Marcos should surrender now instead of being forced out.' There's a certain amount of truth in that, but he has to be vocal to re-establish his credibility after eight years in prison," one State Department official says.

"Aquino's only agenda is to put an end to martial law. He doesn't have an organization, or a positive program in government. That's the dilemma: How to you promote change without an alternative operational program? Now that the government is not as strong in the Philippines, the terrorists are stronger. It's a cruel choice, the source adds. The source concludes that the U.S. has to find a way of supporting the kind of government that would permit change, implying that Aquino might not be the best choice to promote U.S. interests in what the source terms "a volcanic situation."

And Frazier Meade, country director for Philippine Affairs at the State Department, says he doesn't "want to get involved in the competition between Marcos and Aquino," adding, "We abhor and deplore any tendencies toward violence."

Aquino himself expresses gratitude to the U.S., attributing his release to "a tremendous effort on the part of America." On his various excursions to Washington and New York, he urges the United States to refrain from supplying Marcos with "napalm and guns" and asks that America not "intervene--just let us be."