S. Korea returns to reality after the fun and Games. With the Olympics ended, politics is again the chief sport in Seoul. But there are signs that an expected political explosion will be muted. Opposition and official sources say pre-Games negotiations may help avert a crisis over probes into the previous regime's doings.

Today South Korea touches down to earth. With completion of the Olympic Games yesterday, Koreans will have to return to dealing with the realities of daily life.

In the period leading up to and through the Games, the fiercely contending forces in South Korean politics agreed to a truce for the sake of national unity. Now the question is whether the end of the Games will bring a feared crisis, or a continuation of the harmony.

High-level sources in both the ruling and opposition party camps seem to agree that the groundwork has been laid for avoiding a severe clash. Indeed, there is a remarkable degree of unanimity on how to handle the most immediate, pressing issues.

The main source of potential confrontation are two National Assembly investigations into the misdeeds of the previous administration. The opposition-controlled assembly, South Korea's legislature, reconvenes tomorrow. Since earlier this summer, the government of President Roh Tae Woo has been trying to contain these investigations. (President Roh is the handpicked successor of former President Chun Doo Hwan, a fellow ex-general, friend, and military academy classmate.)

One probe is looking into corruption and abuse of power by Mr. Chun and his family. The second panel is looking into the Army suppression of a 1980 antigovernment rebellion in Kwangju, where at least 200 people were killed by troops.

``President Roh is feeling more confident now of his ability to deal with the National Assembly,'' says a top ruling party official. One source of that confidence, the official says, is an understanding which Roh reached with the leaders of the three main opposition parties whom he met privately, and separately, just before the Olympics began Sept. 17.

``The opposition is not in a foul mood,'' the ruling party official contends. ``So we can work it out.''

Opposition sources share the assessment that a formula for solving these issues is in reach. ``If Chun publicly apologizes and returns the property his family got,'' says a senior National Assembly member from the opposition Party for Peace and Democracy (PPD), ``then Chun Doo Hwan can be pardoned.'' This is the view, the official says, of PPD leader Kim Dae Jung, the government's toughest foe.

Feelings against Chun still run deep in Korea. Chun's younger brother was sentenced to prison on corruption charges in a trial which ended last month. Other officials of the Chun administration are also accused of similar abuses. But the most explosive charges are those against Chun and his highly unpopular wife, Lee Soon Ja.

Opposition sources stress that they must satisfy their constituents' desire for justice. ``If the National Assembly fails to show the people anything spectacular, then after the Olympics the pressure coming from some parts of society will be enormous,'' the PPD assemblyman says.

Behind this lurks the fear that Chun and right-wing allies in the military might seek to reassert their power. This summer opposition leaders expressed concerns that such elements, including some within the Roh government, were preparing to launch a crackdown on antigovernment forces after the Olympics. Roh has been depicted as a man caught between his loyalty to Chun and his desire to strike out on a more moderate, conciliatory course.

Both ruling and opposition party sources say President Roh's meetings with the opposition leaders marked a turning point. According to the opposition assemblyman, Roh promised in his private meeting with Mr. Kim and the other opposition leaders, that he would support a public apology by Chun. ``He persuaded them that now the time is ripe, that he is ready to exert his influence on Chun, ready to mobilize his people. Because of that the three leaders came out of the ... conferences situation after the Olympics doesn't seem to be gloomy.''

The military may feel most threatened by the investigation of the Kwangju incident. Some of the officers who commanded the troops are still in service and Army leaders worry about retribution. Kim Dae Jung's party, which has its stronghold in the region around Kwangju, is pushing for a settling of accounts.

But the PPD assemblyman says there is room for compromise on this issue as well. A full airing of the truth, instead of prosecution, he says, may be sufficient.

The opposition wants to clarify the United States' role in the affair. Because some of the troops used to suppress the rebellion were operating under the joint US-Korean command structure, many Koreans believe the US gave support, if not tacit approval, to the repression.

According to an informed US source, the State Department is now preparing a full statement on the US role. US officials have stressed their support for a full airing of the facts, confident it will show no US responsibility. This summer a National Assembly committee sought the direct testimony of the former US ambassador and senior US military commander at the time. But opposition sources say a written statement may be sufficient.

All sides agree that this compromise approach depends on Chun's willingness to make a public confession of his misdeeds. Some observers doubt that the stern former military leader can bring himself to admit his own wrongdoing.

But there are signs that Chun is feeling the heat. He yielded to pressure in not attending the opening ceremony of the Olympic Games, an appearance that many feared would trigger an angry audience reaction. That decision, says a Western diplomat, ``is interpreted as a sign that Chun will cooperate in some fashion with the investigations to help the [ruling] Democratic Justice Party.''