Calm follows turbulence in South Korea

South Korea closes out the Year of the Cock with apparent political stability and a more hopeful economic climate than at the beginning of the year. President Chun Doo Hwan seems in firm control of the so-called Fifth Republic and its institutions, all of which are in place. At home, there is no immediate threat to his regime, and in terms of security and of foreign policy, he has the essential support of the Reagan administration.

Small student on-campus demonstrations still erupt from time to time, but they are crushed swiftly and methodically. The massive, unruly demonstrations during the spring of 1980 seem a distant memory.

''Business is terrible,'' says a small clothes manufacturer, ''but I certainly don't want any disturbances. I am willing to judge this government by what it manages to do for the economy.''

For citizens old enough to remember the Korean War, security is still the primary consideration. They worry that their children, who are growing up in peace and increasing affluence, tend to forget the essential distinction between the completely closed, totalitarian regime of North Korea, and successive southern regimes. These have been authoritarian, but they have tolerated degrees of opposition, and they have encouraged a soaring per capita income that has gone from $81 in 1961 to more than $1500 today.

An outside visitor to Seoul finds the current political scene curiously quiescent, considering periods, even during the late President Park's 18-year rule, when the press was more free, the opposition more vocal, and the president himself forced to stand for re-election in gruelling, hotly-argued campaigns.

Newspapers censor themselves, professors visit their students' homes to persuade them not to demonstrate. The government arm is long, and pervasive. But although martial law is ended, a new constitution proclaimed, and a new National Assembly in place, there is not as yet a sense of political normality.

For the first time, the United States has a political appointee as ambassador to Korea - Professor Richard Walker of South Carolina. Cheerful, gregarious, a well-known scholar on China and East Asia, Ambassador Walker is a political conservative highly conscious of the dilemma democratic societies face when confronting repressive communist regimes.

In a speech in October which drew wide attention within the intellectual community here in Seoul, Mr. Walker asked, ''How can we maintain security against the totalitarian practices to the north without succumbing to the mirror image trap?''

He continued, ''Given the zone of silence in the north, it becomes doubly important to sustain freedom of expression and freedom of exchange of ideas here in the Republic of Korea. . .

''I realize the problem and the contradiction involved in defining academic freedom and press freedom as opposed to license. The Americans perhaps mistakenly go too far in the direction of freedom. But we also feel that history sustains us, that it is better to err in this direction. Academic and cultural freedom are positive causes which we must embrace.''

The speech drew no official response. Privately, some government sources maintain that it is mistaken to talk of freedom and of human rights as if they were universal, inalienable human values, that degrees of freedom have always differed from society to society, and that what is appropriate for a society in one stage of development may be totally wrong for a different type of society.

In any case, they say, there is no comparison between the amount of personal freedom and choice an individual enjoys in the south, and the almost total lack of such freedom in the north.

Among the former generals and colonels who have been brought into the Blue House, the executive mansion, or into other prominent positions, many are conceded to be men of honest intent, patriotic, and capable administrators. Certainly they are nationalists. At the same time the group as a whole seems to remain thin-skinned, extremely sensitive to criticism of any kind.

A number of Korean observers believe that whether the regime evolves in the direction of greater freedom of political expression depends in large measure on how it copes with the economy next year. It has brought inflation down to close to 14 percent and hopes to get into single digit figures next year. It has also managed to achieve 7 percent economic growth and hopes to continue at the same rate next year.

Wage negotiations coming up in the spring will be the first test of how successful these projections will turn out to be. So far workers have willy-nilly accepted the government's argument that inflation must be squeezed out even at the cost of some reduction in living standards. Can they be persuaded to do so again? Restive workers and volatile students make an explosive political brew, a fact of which the government is well aware and which accounts in part for its extreme nervousness over any public manifestations of discontent.