In a series of quiet and remarkably amicable meetings here in the past few days, government and opposition politicians agreed to equal representation on a committee that will revise the constitution left by the assassinated president, Park Chung Hee.

Over the same few days, on the streets of Seoul, police and martial law forces were moving quickly to break up dissidents who gather to protest the election as caretaker president of a man who was close to the late president.

As these two series of events suggest, politics in post-Park South Korea is running on two parallel tracks. On one track there is a mood of compromise and political accommodation. On the other, there is deep resentment of all politicians and a commitment to defiance that is met with strict suppression.

The parallel trends reflect the interests of those involved -- the talks being pressed by the civilian politicians in Park's political party and the repression of militant opposition by the martial law authorities. While each side is pursuing its own interests, there are no signs that either disapproves of what the other is doing.

A month after Park was shot by his own intelligence chief, it is unclear which of the two will prevail. Some observers believe that, for the first time in years, South Korea is entering a phase of democratic politics in which the National Assembly will emerge as a forum of debate and influence. Others think the country is descending into a new cycle of protest and repression that eventually will put a new strong man in the Blue House, the presidential mansion.

The signs are mixed and often contradictory. The interim government headed by acting president Choi Kyu Hah has privately extended several olive branches to the opposition and has won a measure of approval.

His government has quietly begun releasing some of the political prisoners jailed by Park. Last weekend, it released Moon Boo Shik, the opposition New Democratic Party editor who had been imprisoned for trying to publish a special edition criticizing Park's police.

Another opposition party aide was also released and Choi's ministers have privately leaked word that more will be freed within a month. It is hinted that the most celebrated opponent, Kim Dae Jung, will be freed from house arrest and that many arrested students barred from colleges will be reinstated after a review by government ministries.

Yet, while those signs of accommodation were emerging, club-swinging police, acting under martial law orders, broke up the first demonstration held since Park's assassination, and arrested at least 40 young activists. All may face several years in prison.

Almost simultaneously, martial law authorities arrested several prominent religious and intellectual leaders in a roundup of 85 dissidents who violated military orders by holding an unauthorized gathering in downtown Seoul.

Sources here expect more protests and more arrests of persons opposed both to Choi's selection as caretaker president and to the censorship and other restrictions enforced by the martial law command.

Employes of one broadcasting station have defied authorities by issuing a statement promising to report and edit news according to their own judgments. aA campus activist group has called for abolition of surveillance at colleges, immediate reinstatement of jailed students, and an end to student military training.

In response, the Military Law Command has announced that it will crack down on any demonstrations and that martial law will continue in force indefinitely.

The dissidents themselves are divided over what course to follow -- whether to protest any change short of a free election or whether to give Choi a chance to demonstrate a sense of reform as caretaker for a year or so.

Choi has been promised cooperation by a group of religious leaders, including Cardinal Stephen Kim Sou Hwan, who in the past has been a frequent critic but who is now convinced the government will free political prisoners.

Choi, however, has not won over another dissident group which informally looks for guidance to Yun Po Sun, the former South Korean president recently released from house arrest. Choi, he says, was Park's number two man who was devoted to the late president's dictatorial policies."

"And now they are trying to make him an acting president," Yun added in an interview last week. "I think this could be a betrayal of what people want."

Among politicians in the National Assembly, the new mood of compromise is a sharp change from the past and seems to be embraced by virtually every element of both the government and opposition parties.

The key test was last weekend's negotiations over membership of the committee that will rewrite the old constitution which was the basis of Park's rule for seven years. After a couple of days of haggling, the pro-government Democratic Republic Party agreed to give the opposition party equal representation on the committee. The compromise was largely the work of Kim Jong Pil, the government party's new president and a man widely believed intent on occupying the presidential mansion after a year of constitutional revision.

The American Embassy here has played a low-profile role in encouraging the compromises. It has urged both sides to talk out their differences and called on the pro-government forces to broaden the political base to embrace Park's critics. It is also believed that American officials have encouraged the military command to relax some restrictions.

The official U.S. position is to avoid taking sides in any disputes. Yet it abandoned that position publicly by issuing a prompt affirmation of the decision two weeks ago to have a caretaker's election under the old constitution at a time when virtually all opposition leaders wanted to amend the constitution first.

That endorsement embittered some dissidents, including former president Yun who described it as "very far apart from the true feelings of the Korean people." But other antigovernment leaders, including opposition party president Kim Young Sam, pointedly declined to criticize the American intervention.