SEOUL -- These are frenetic and exciting times for South Korea. Next month there will be a democratic presidential election for the first time in 16 years and next September Seoul will be the host city for the 24th Summer Olympic Games.

Six years ago, neither of these two events seemed possible in this country of 42 million. Politically, the country was firmly in the grip of President Chun Doo Hwan, who had seized power in a 1979 military coup, and the Olympics appeared way beyond the means of any city short of one the size of Moscow or Los Angeles.

But after an explosive summer of strikes by thousands of workers, almost daily protests by students and many middle-class citizens, the newly nominated leader of the ruling party stunned his fellow citizens and much of the rest of the world by calling for reforms and direct democratic elections.

And if the sights and sounds of ruling party candidate Roh Tae Woo matching words and photo opportunities with opposition candidates Kim Young Sam, Kim Dae Jung and Kim Jong Pil were unique for the country, what about the almost completed Olympic skyline?

Stadiums, gymnasiums, arenas, parks, velodromes, an Olympic Village, indoor swimming pool -- 23 venues in all, costing $3.1 billion -- have sprouted to near completion since 1981, when the top members of the Seoul Olympic Organizing Committee convinced the members of the International Olympic Committee their city could do a better job of hosting the Games than Nagoya, Japan.

In fact, Nagoya was Seoul's only competition for being the host city, a key factor in its being selected because the Games were in Tokyo as recently as 1964. Also, the appeal for other countries to bid was reduced considerably by the U.S.-led boycott of the 1980 Moscow Games.

"Let's face it, we got the Olympics because nobody else wanted them," said Park Shin Il, director of the Korean Overseas Information Services, in an interview here last week. "But if you only gave the Olympics to the few perfect cities, who else would have a chance?

"This is our chance," Park continued, noting, as do many of his government colleagues, that Japan used the 1964 Games as a springboard into the economic elite of the world. "More than anything else, we need the boost a successful Olympics can provide. We deserve a better image. People still have weird ideas of this country. Dark images . . . the M*A*S*H* syndrome . . . military state.

"Thanks to the Olympics, this already has become a more democratic country," Park said.

While workmen put the finishing touches on the Olympic Village and indoor swimming pool (all other venues are completed) and political debates continue nonstop, questions and issues surrounding the Games to be held Sept. 17-Oct. 2 are hot topics. They include: Will North Korea agree to the International Olympic Committee's proposal to host five events and participate in the Games? And, if the North Koreans decline, will other communist countries boycott the Games?Can the South Koreans, in light of the internal problems of the past year and general international tensions and threats of terrorism, provide the security and acceptable environment for a safe Olympics?Will the Seoul Olympics be as successful financially as the Los Angeles Olympics of 1984, or does the possibility of another economic debacle such as Montreal experienced in 1976 loom? What kind of facilities await the athletes, spectators and television viewers?

Of all the issues, none stirs the emotions here as much as the subject of North Korea, which was supposed to give the IOC its decision last summer, but didn't, probably because, as one Seoul Olympic Organizing Committee member says, "It wants to see how our elections come out." North Korea has until Jan. 17 to make its decision.

The IOC, with the agreement of the SOOC, has offered North Korea the opportunity to hold the finals in archery, table tennis and women's volleyball, a preliminary round in soccer and a bicycle race that would start in the North and finish in the South.

The country has been divided since the United States and Soviet Union ended the Japanese occupation in 1945, followed by a bitter war (1950-53). Formal relations between the North and South are nonexistent, although an exchange takes place occasionally and contacts are increasing. So Olympic and government officials are skeptical that North Korea, which is far less developed than South Korea, even wants to become involved in the Olympics.

"Time is running out," said Kim Un Young, South Korea's representive to the IOC and a key figure in the planning of the Games. "It's obvious they are waiting for our elections before making a decision."

If North Korea agrees to host those five events, it would have to open its border, something it has never done, and allow free movement from the air and ground to Pyongyang. "I don't know how they could get people to the place, other than by plane. There isn't even a road," said Park Shin Il.

The North Korean border is only 25 miles from Seoul and is among the most heavily fortified, on both sides, in the world, including 40,000 U.S. troops.

The president of SOOC, Park Seh Jik, said the delay by the North Koreans has caused his organization great difficulty.

"In a sense, we've had to prepare for two Games," he said. "One, if all the events are here; the other if the North Koreans decide to participate."

Added Cho Sang Ho, South Korea's minister of sports: "If they participated, the atmosphere would be easier. But nobody knows what they're going to do."

North Korean officials, who did not respond to a request for an interview last week, previously have stated their desire to "co-host" the Games and to be involved to a greater degree than the IOC is offering.

Last week however, it was reported that North Korea recently renewed a previous suggestion to the IOC that the two countries field a unified Olympic team, with all events in the south. But South Korea is likely to reject that proposal.

SOOC officials maintain the IOC awarded the Games to Seoul and "not the country of Korea."

Still, some wonder about the chaos that could develop if the North Koreans simply said yes and came to play.

"But they'll probably say no," one SOOC associate said, "because they know if they start a bike race in the North, 50,000 will come down and 5,000 will go back."

As can be imagined, because of the political climate some critics wonder if Seoul is a suitable place to hold the Games. But SOOC officials do not expect a repeat of last summer's downtown Seoul demonstrations, many of which were violent. "None of the political factions are against the Seoul Olympics," said President Park. "Whichever party wins the election will support us because the Olympics transcend political differences."

This "national obsession" will cost the country $3.1 billion, which includes not only construction of the venues, but that of a press village, the cleanup of the Han River, new subway lines and an urban renewal project.

But SOOC officials are confident the Games will pay for themselves, although some Koreans (the per capita income is under $3,000) wonder. The apartments in the Olympic and press villages have been sold for use after the Games; officials expect 240,000 tourists to jam Seoul (all the hotel rooms supposedly are booked, although the U.S. remains one of the few countries without an official ticket/travel agency) and the government will receive between $300 million and $500 million in broadcast rights from NBC-TV, as well as money from other television outlets throughout the world.

In addition, SOOC followed the lead of Peter Ueberroth, former president of the Los Angeles Olympic Committee, and lined up such corporate heavies as Kodak, IBM, Coca-Cola, Federal Express, Time Inc., Visa, 3M and Brother International Corp. for big-money sponsorship.

"We expect a tremendous economic impact from the Olympic Games," said the IOC's Kim. "There are two ways to go in hosting the Games: starting from scratch, like Tokyo and Montreal, or doing what L.A. did in using existing facilities.

"L.A. paid a few bucks to the Los Angeles Coliseum and went from there," Kim continued. "We had to start from scratch. But we want to make use of the facilities when the Games are completed."

What the athletes and spectators will find next September are state-of-the-art stadiums and arenas comparable with the best in the United States, in two convenient locations: The Seoul Sports Complex and the Olympic Park. Both sites are close to the Olympic Village and within several miles of the central city. Last year's Asian Games proved to be a good dress rehearsal, officials said, although there were some complaints about transportation and traffic problems.

The organizers are trying to prepare for every eventuality, said Kim, although he added, tongue in cheek, that "problems could arise. Like what would happen if Martina Navratilova decides to enter the tennis {now open} competition. What will we do with her entourage?"