"It is difficult," said South Korean shop owner Kim Yong Ju as he sat in a Seoul coffee house last week, "but not impossible."

There are few Koreans who dismiss reunification of their country, divided since 1945, as a hopeless dream. In both North and South, the goal of a single, independent nation is deeply ingrained in official ideology and popular thinking.

On the face of it, the dialogue that the two rival governments began last month with the unprecedented delivery of flood relief aid from North to South makes that goal a bit less unreachable.

Yet, even as they praise unity as a sacred national duty, North and South are pursuing radically different strategies of development as if the other did not exist.

Many analysts here feel that the best possible result of the talks would be to reduce tension between the opposing sides. The two now have 1.2 million troops arrayed against each other and are heavily burdened by military spending -- 6 percent of gross national product in the South and as much as 24 percent in the North.

In the long run, trust would let them cut this spending and put people into productive work. They then would pursue their opposing development strategies in peace, the thinking goes.

Some Koreans feel there is a model in Germany, another country left divided by World War II. In contrast to Korea, its two sides trade, allow mail and some cross-border travel and maintain a comparatively cordial dialogue, although unification is nowhere in sight.

"Peace precedes the process of reunification," said Lee Jong Ryool, information and analysis chief for South Korea's ruling Democratic Justice Party.

"If we can achieve some type of cooperation like East and West Germany have achieved in the last 10 years, I think that would be very helpful to us."

Progress between the two parties is a real concern for ordinary Koreans. The Demilitarized Zone separating the two nations is an impenetrable barrier. Millions of people in North and South have relatives on the other side from whom they have not heard in 30 years or more.

Leaders on both sides continue to assure their own people that one Korea is the goal. Indeed, praising it appears to be an important part of establishing credentials as a political figure.

North Korean President Kim Il Sung rarely speaks without stating, as he did in a message to Soviet leaders on Korean independence day, the need for an "independent, peaceful reunification of the country."

In its capital, Pyongyang, North Korea maintains a Committee for the Peaceful Reunification of the Fatherland whose ostensible goal is to foster a merger with the South.

The South Korean government, in turn, has the National Reunification Board with headquarters in a three-story building in Seoul and a staff of more than 300 persons. Its chief, Sohn Jae Shik, has Cabinet rank.

South Korean President Chun Doo Hwan, in a message to the National Assembly last week, pledged efforts to "change the present Seoul-Pyongyang confrontation into the South-North Korean cooperation to pave the way for national reunification."

The division dates to 1945. As Korea was liberated from Japanese colonial rule, Soviet troops moved in to occupy the North and U.S. troops entered the South. Forty years later, after a three-year war that ended in 1953, they remain intractably divided.

South Korea remains allied with the United States, which maintains 40,000 troops there. It is building a strong, export-oriented economy, while its political system wavers between parliamentary democracy and military authoritarianism.

Its economic planners make no assumption of ever having access to the natural resources of the North. Importing what it needs from abroad, the Seoul government is pursuing a classic development strategy for capitalist countries.

North Korea favors "self-reliance," with little foreign trade and factories producing a large number of products for a relatively small home market. Politics are dominated by Kim Il Sung, around whom a personality cult has been built.

Hatred between the two sides remains intense and officially encouraged. The North Korean media habitually refer to the South's Chun as a "flunkey-traitor," "butcher" and "man inferior to a dog."

Kim Il Sung, in turn, can be the subject of derisive laughter in Seoul. One South Korean official took delight recently in pointing out that Kim's son and heir apparent, Kim Jong Il, was shown wearing high-heeled boots in a North Korean magazine.

The North's offer of flood aid last month touched off a debate within the South Korean government. Western diplomats say the decision to accept the aid, which might imply that the South was unable to care for its own people, was based on new self-confidence the South has achieved.

It comes at a time when Chun is slowly loosening, by South Korean standards, controls on the opposition and plans elections early next year. He has restored the political rights of all but 99 dissidents who were banned after he came to power in 1980.

The campaign for democratic rights by opposition circles is in a lull. Opponents of Chun complain that their best people remain under political ban, that the election law will favor the government party and that Chun's reforms are largely a sham.

In both government and opposition circles there is a feeling that the return of exiled dissident leader Kim Dae Jung, who has said he will come home by year's end, could provide a new impetus for the campaign against Chun's rule.

On the economic front, the South Korean economy has recovered from major dislocations brought on by world recession and political unrest in 1980 and 1981.

Anxious to foster an image of statesmanship, Chun apparently felt nothing would be gained by turning down the North's offer, although the South remains deeply suspicious that it may mask some violent intent.

South Korean officials continue to point to the bomb blast in Rangoon a year ago that killed 17 South Koreans, including four Cabinet ministers. Burma blamed North Korean agents for the blast. This weekend, rallies to protest the bombing were held in Seoul.

With the aid transfer completed, the two sides are now discussing further talks on sports cooperation and other humanitarian exchanges.

Most western analysts, however, believe that whatever the North is seeking, the international situation holds promise for progress. China, one of the North's prime patrons, is slowly building unofficial links with the South. There are signs also of improving ties between the North and Japan, which is close to South Korea.