One of the hottest wars in the history of the international car industry is about to take place on U.S. soil.

The prospective combatants are Koreans and Japanese. And American auto workers may get caught in the cross fire.

The objective is domination of the U.S. small-car market, which accounted for 32.6 percent of all cars sold in the United States last year.

"It's going to be a blood bath," said Christopher Cedergren, senior automotive analyst for J. D. Power & Associates, a national auto-market-research firm based in California. "The Koreans are going to be as much of a threat to the Japanese as the Japanese have been to the Americans."

Hyundai Motor Co., Korea's largest car company, is leading the Korean assault. The first Hyundai -- the front-wheel-drive, 1.5-liter, 4-cylinder Excel -- goes on sale in the United States on Feb. 20. The car will carry a base price of $4,995, an estimated $742 less than the $5,737 average price of competitive Japanese models.

Hyundai (pronounced "hun-day") expects to sell 100,000 Excels and related models in the United States this year. By auto industry standards, that is a small beginning. A single General Motors Co. plant can produce and sell 200,000 cars a year.

But Max Jamiesson, executive vice president and chief operating officer of California-based Hyundai Motor America, Hyndai's marketing arm, said that a 100,000-unit sales year will be more than enough to justify his company's decision to take on the Japanese in America. If all goes well, Hyundai might even adopt another Japanese strategy and build its own assembly facility in the United States, Jamiesson said.

"It all depends. . .," Jamiesson said to reporters at a recent meeting of the National Automobile Dealers Association in New Orleans. "We haven't yet sold a car in this country."

Analysts expect Hyundai to sell a lot of cars very quickly, benefiting from the reputation for quality that it built selling cars in Canada and from the absence of significant low-priced competition in this country.

"At the moment, there really aren't any $5,000 cars made in the United States because the profit margins on those kinds of cars are little, or nonexistent," said David Healy of Drexel Burnham Lambert in New York. "And many of the $6,000 cars produced here are models that most people don't want anyway."

The vacuum for good new cars in the $6,000 base-price range largely has been filled by the Japanese. Examples include the Toyota Tercel, $5,598; Nissan Sentra, $5,649; and the Honda Civic, $5,649.

American companies, despite Healy's criticism, do have worthy cars in the entry-level range. But in an effort to boost profit per unit, these companies often load their "base" cars with extras, frequently pushing their final sales prices over the $7,000 mark.

Power & Associate's Cedergren said he believes that Hyundai will have no problem meeting its initial goals in the United States judging by its stunning performance in Canada.

Hyundai entered the Canadian market in 1984 intending to sell 5,000 subcompact, rear-wheel-drive Pony II cars. The company sold 25,000 of those models. Last year, sales more than doubled, pushing Hyundai past Japan's Honda Motor Co. Ltd. to become the top-selling import in Canada.

Hyundai's sales success in Canada also did something else for the company and perhaps for its Korean peers. It established Hyndai's reputation as a quality manufacturer, Cedergren said.

"What the Koreans have going for them now is that they appear to have the same quality image as the Japanese," Cedergren said. And by carefully setting up a distribution base of 200 "exclusive, high-quality dealers" in the United States this year, Hyundai is going to build that image, he said.

"The Koreans have pretty good quality for the money" they are asking for their cars, said James Harbour, a Detroit-area auto industry analyst. "They have gotten smart enough to realize that, if they're going to expand their home economy, they're going to have to build something that they can sell in the United States."

Harbour said that Hyundai used Canada as a test ground and staging area for its movement into the U.S. market. "Obviously, Korea is now a threat to Japan" in North America, Harbour said. Korea's U.S. campaign means "that it's going to be a war in the U.S. auto market."

The two Asian countries are no strangers to conflict. Japan colonized Korea in 1910 and kept the country under its military thumb for 35 years. Even in the balmy climate of New Orleans last week, amidst the tinkling of cocktail glasses in NADA hospitality suites, Korean officials of Hyundai spoke bitterly of those years of occupation.

But the Koreans agreed with Harbour, saying that their automotive push into North America stems more from their need to expand their country's industrial base than it does from any lingering desire for vengeance.

In addition to Hyundai, the expansion of Korea's auto sector will be led by Daewoo Motor Co., which is 50 percent-owned by GM, and by Kia Industrial Co., which is 10 percent-owned by Japan's Mazda Motor Corp.

"Each of these firms has begun expansion projects, with combined capacity to reach 756,000 units by 1987," according to a June 1985 report on the Korean auto industry, prepared by the U.S. Embassy in Seoul.

"Unless tremendous growth occurs within the Korean auto market, a majority of those cars produced in 1987 are likely to be exported. All three companies have developed strategies to enter the U.S. market, the designated recipient of excess capacity," the U.S. Embasssy report said.

A key to the Koreans' ability to break in to the U.S. market is their lower labor costs, most analysts agree. Korean auto workers average $2.16 an hour in wages and benefits, compared with $13 an hour in Japan and $25 an hour in the United States, Healy said.

This, in turn, will put even more pressure on U.S. producers.

The Americans finally are catching up with Japanese quality, most industry analysts believe. But U.S. companies still trail the Japanese by as much as $2,000 a unit in production costs.

U.S. auto makers, as a result, have started shifting their small-car production overseas in a drive to reduce their manufacturing costs.

The arrival of the Koreans will make it virtually impossible for the Americans to reverse overseas-sourcing movement. Instead, according to Healy, the Korean push will force the Americans to accelerate their foreign-supply programs.

That means continued U.S. production of small cars such as Ford Motor Co.'s Escort and Chrysler Corp.'s Omni/Horizon series could be endangered, thus jeopardizing thousands of U.S. auto jobs, according to Healy and other analysts.

U.S. and Japanese auto officials tend to play down the Korean threat. "I don't think that they're going to walk away with the U.S. market," Ford President Harold A. Poling said of the Koreans.

Poling said that the quality of the Hyundai is "pretty good," but that it does not yet match the quality of comparable American and Japanese products.

"I think that they're going to get a lot of the people who are looking for low-priced cars."

But Poling conceded that the Koreans could be a factor in encouraging his company to look overseas for more small cars, particularly for the minicars that would be difficult to produce and sell profitably in the United States.

Ford, for example, intends bring in a Mazda-designed, Korean-made minicar in 1987. The car, which some industry observers say will be called the Ford Festiva, will be made by Kia.

First-year U.S. sales of the Festiva are expected to reach 70,000 units, industry sources say.

Ford officials declined comment on specifics about their Kia-import plan.

In addition, Ford will rely on its Taiwanese partner, Lio Ho, as a small-car source.

GM intends to use its relationship with Daewoo to similar advantage, relying on its Korean partner to produce about 80,000 Maepsy compact cars annually for U.S. sales.

The Daewoo mobiles, which will be sold by GM's Pontiac dealers as the Pontiac Le Mans, are expected to roll into U.S. showrooms in early 1987. The model will complement GM's growing small-car lineups from its Japanese partners, Isuzu Motors Ltd. and Suzuki Motor Co. Ltd.

Chrysler, whose extensive line of U.S. and Japanese-made small cars could take a direct hit from the Koreans, also is turning to a Korean partner to protect its flanks.

Chrysler last April signed a parts supply and production agreement with Korea's Samsung Group. The Korean government does not now allow Samsung to produce cars.

But the U.S. Embassy report said: "According to almost all observers, events will force the Korean government's hand, and we will see 100,000 Samsung cars annually roll off the assembly line by the end of the decade.

"Most expect that Chrysler-Samsung will be able to offer a package that the government won't be able to turn down," the report said.

And the Japanese?

Some think they'd rather switch than fight.

"The likelihood is that the Japanese will say to the Koreans: 'Okay, you want the small-car market. Be my guest. The profit margins on small cars are low anyway,' " Harbour said.

But other analysts disagree. "Neither the domestic nor the Japanese manufacturers will vacate the low end of the U.S. market," Cedergren said. To meet production goals, they will need full lines of cars. "There's only so much room at the top of the market, only so many people can affort to buy upscale cars," he said.

At the same time, the Japanese are expected to do what the Americans are doing: move production to cheaper countries. For example, Nissan Motor Co. Ltd. announced earlier this month that it will join forces with Daewoo to begin producing a series of minivans for the Korean market.