Why some South Koreans resent American backing

When South Korean opposition figure Kim Young Sam, began a hunger strike May 17 in protest against lack of democracy in South Korea, he also took a swing at the United States.

He blamed the US for supporting President Chun Doo Hwan's regime, saying, ''America can be seen to be supporting the suppression of human rights.'' He also described last year's arson attack by Korean students on an American cultural center in Pusan as a ''mortal wound to American-Korean relations.''

Mr. Kim's statement, while primarily criticizing the South Korean goverjment, is part of a noticeable undercurrent of dissatisfaction with the country's chief ally.

Most observers agree that a low level of resentment against the US is fairly widespread, stemming largely from Korea's national character as well as its military and economic dependence on a powerful nation. ''Koreans are nationalistic, proud, and a little nouveau riche. . . . The xenophobia is fairly normal,'' said one Western diplomat.

The presence of up to 40,000 American soldiers in South Korea inevitably causes problems, though the Korean authorities are skillful at isolating the US military communities and lenient in dealing with GI crimes.

The ''melting pot'' of a heterogeneous US could hardly be more different in terms of social values from homogeneous, neo-Confucian Korea. In addition, quite a few Koreans are worried that the moral laxity and crime of the US will spread to Korea.

Although this underlying resentment could perhaps provide a fertile ground for future seeds of discontent, it is balanced by a continuing gratitude for the US military support, especially among the older generation which was involved in the Korean war.

Most South Koreans are also well aware of the practical advantages in having good relations with the US: it is South Korea's largest trading partner, and the close alliance is the bulwark of the republic's high creditworthiness, especially at a time when South Korea carries one of the highest debt burdens in Asia.

Of course the advantages work both ways. South Korea not only stands as a floodgate against communism in northeast Asia, but it is also becoming an important market for US goods and services. ''It's a useful relationship to both of us; we should make the necessary adjustments to keep it that way,'' said an American official in Seoul.

There does exist, however, radically anti-American groups - small but vocal, and sometimes actively militant. They include:

* Students who resent both US dominance and political support for Chun;

* So-called ''Christian Dissidents,'' especially Roman Catholics, who criticise the US for not leaning more heavily on Chun to improve South Korea's human rights situation;

* And liberals who are worried by the trend to conservatism under President Reagan and by Korea's return to ''one-man politics.''

Some priests, missionaries, university lecturers and others closely involved, say the dissidents' militancy has increased rather than declined, albeit underground, since it was sparked off by the apparent cooperation of the US military leaders in Seoul with then General Chun in brutally crushing a 1980 rebellion in Kwangju.

American and Korean officials, however, say they do not expect anti-Americanism to increase unless there are some unexpected, fundamental changes. ''The possibility of it ever becoming really virulent is very remote,'' said an American observer, ''but we could have problems if, for example, Chun does not step down (when his term of office expires in 1988) and the US fails to oppose it.''

As for Mr. Kim, a one-time candidate for president, he has spent nearly two of the past three years under house arrest. He is banned from political activity until 1988. Few consider him a serious threat to it. Nevertheless, his refusal to admit defeat is a reminder that some of the problems President Chun swept under the military carpet when he first came to power, are still lurking there. And Kim's comment on the US is a reminder that anti-Americanism is one of them.