Economic growth is enabling South Korea to reach out to its Asian neighbors and to countries around the world - especially the nonaligned ones.
In its foreign policy, South Korea seems to be trying to present itself as one of the developing countries, an alternative trading and diplomatic partner to both Japan and communist North Korea.
South Korea's close ties with the United States have kept it from being accepted as a member of the nonaligned movement. (The North, however, seems to qualify, despite close Soviet and Chinese links.) And so apparently the next best thing is to establish relations with as many developing countries as possible.
''Many of these countries are in the same stage of development as we are, with common economic and social problems. We can identify with them closely,'' says a high official of the Foreign Ministry.
There now are 64 countries that recognize both Koreas, many of them in the third world, the official explains.
''Our main effort is to demonstrate to these countries that there is a stronger and more prosperous Korea (to the south). And it is a fact that once we move into such countries, our relations with them become more substantial than North Korea's.''
The South Koreans feel they have a lot more, economically, to offer any developing country - such as rapid expansion of two-way trade and industrial know-how, especially in construction.
Above all, however, Seoul wants to convince the nonaligned world that it is reasonable and that it is Pyongyang which is intransigent over the issue of Korean reunification.
While consolidating diplomatic contacts in Asia, South Korea is also moving farther afield. Both trade and political considerations dictate a much stronger effort in the Middle East, Africa, and South America. Missions have been established recently in Lebanon, Libya, Iraq, and Nigeria.
As part of its special effort in Africa, where North Korea is making its presence felt, Seoul is pursuing an extremely harsh anti-South African line, even though South African troops fought on the South's side in the Korean war.
South Korea is also pursuing ties with Pakistan, Belize, Trinidad and Tobago, the Bahamas, and Cuba.
Stressing ''invitational diplomacy'' the Foreign Ministry has asked some three dozen high officials from Africa, Central America, and the Caribbean this year to visit. Seoul is also striving to promote East-bloc contacts - nonpolitical exchanges with China and Eastern Europe, for example.
This is also part of an attempt to encourage the greatest possible communist participation in the 1988 Olympic Games in Seoul, at which North Korea is generally expected to be conspicuous by its absence.
Closer to home, President Chun Doo Hwan has been cultivating the Association of Southeast Asian Nations (ASEAN). He made a comprehensive tour of ASEAN's five member nations - Malaysia, the Philippines, Thailand, Indonesia, and Singapore - last July. He took along half his government and the elite of the Korean business community to forge stronger political and economic ties with the bloc.
The South Koreans are demonstrating that they can compete with Japan not only for ASEAN's natural resources but also for a bigger share of its trade.
One diplomatic analyst says: ''I think the Koreans are ideally placed to take advantage of ASEAN's growing importance. Within this region there is still lingering suspicion of the Japanese, partly because of the war and also because they are simply too rich and powerful.
''But Korea doesn't have those hang-ups. First, it too was under Japanese military domination. Second, it is a country today just like those of ASEAN, trying to pull itself up by its own bootstraps.
''The people in ASEAN can see this and appreciate it. They can accept Korean aid and trade without feeling dominated and patronized.''
Among the five ASEAN members, Malaysia and Indonesia are now ranked in the top 10 exporters to Korea. Overall, Korean imports from the region have grown over the past 10 years from $166 million to over $1.5 billion. Korean exports have expanded similarly: from $29 million to $1.2 billion.
And Seoul officials reckon this is just the beginning.
A breakdown of Korean involvement in the five countries today looks something like this:
* Indonesia: Access to the country's energy is South Korea's major goal. It has signed a long-term crude oil import agreement with Jakarta authorities and is also engaged in joint oil exploration off the Indonesian coast. Korea is also supposed to get large quantities of Indonesian liquefied natural gas, now exclusively supplied to Japan, but at this writing the two sides are hung up on price, as well as details of Korean financing for liquefaction and transportation facilities in Sumatra. Korean and Indonesian construction firms also plan to work together in third countries.
* Malaysia: Korean firms are involved in the mammoth Penang bridge project and also have big orders for industrial plant construction. The Koreans want to tap Malaysia's rich natural resources in return for scientific and technological cooperation, personnel training, and economic aid.
* Singapore: Partnerships in cement and plastics already exist and joint ventures in shipbuilding and electronics are under consideration. Korea's home-produced Hyundai Pony passenger car is to be launched in Asian-Pacific markets through a Singapore-based operation. Korean construction firms are highly active in the island republic's development, along with an estimate 40 companies representing banks, trading houses, and shipping firms.
* The Philippines: Business relations are few, although Korean construction firms have won orders worth several hundred million dollars recently and several areas of investment are in the preliminary stage of discussion.
* Thailand: Even though Thailand is a major supplier of rice to Korea, there has not developed a big market for Korean goods. Several heavy industrial projects are reported to be in the offing.