SEOUL (NYTIMES) - The last time South Korea hosted an Olympics, in 1988, the North not only refused to take part, it blew up a South Korean airliner 10 months before the games.

Yet, South Koreans at the time expressed hope that the two Koreas, divided by the Cold War, could one day become a single nation again.

Now, as the South prepares to host its second games next month (February), the Koreas are cooperating in unheard-of ways, including their first joint Olympic team, in women's ice hockey.

But South Koreans, especially younger ones, are far less interested in reconciliation, to say nothing of reunification.

Experts and recent surveys describe a profound shift in attitudes in South Korea, where reuniting the peninsula, and the Korean people, was long held as a sacrosanct goal.

These days, younger South Koreans in particular are far more likely to see the idea of reintegrating their prosperous capitalist democracy with the impoverished, totalitarian North as unrealistic and undesirable.

"I personally wouldn't welcome reunification because it would create a burden for us, as we would have to help rebuild the North Korean economy," said college student Park Min Cheol, 22.

Young Koreans say they are more concerned about pressing domestic issues - such as unemployment, and whether they can live as well as their parents did - than the enormously costly, complex and hypothetical task of reunifying with the North.

The reunification of Germany in 1990 serves to some as an example of how arduous, and expensive, rejoining two very different societies can be, and the economic gap between the two Koreas today is much wider than it was between East and West Germany.

In polls, fewer respond to the old appeals to common ethnic heritage, much less the shrill, propagandistic calls for reunification put forth by North Korea.

A survey last year (2017) by the government-run Korea Institute for National Unification in Seoul found that far more South Koreans in their 20s now oppose reunification - 71.2 per cent - than support it. Across the population, support has dropped to 57.8 per cent from 69.3 per cent just four years ago.

"Especially men in their 20s, about half of them, consider North Korea an outright enemy," said research fellow Kim Ji Yoon at the Asan Institute for Policy Studies in Seoul who has been tracking attitudes toward reunification. "To young South Koreans, North Korea is someone they don't want anything to do with."

Polling experts say that South Korean men in their 20s often get more hawkish after they finish their mandatory military service.

The scepticism was apparent this month (January), when the two Koreas set aside their disputes over the North's nuclear weapons and missile programmes and agreed to field a joint team in the Winter Games in the town of Pyeongchang, and to march together in the opening ceremony on Feb 9.

In the past, such gestures triggered waves of pro-unification sentiment, as in 2000, when North and South Korean athletes marched together at the games in Sydney, Australia. (They competed separately.)

The administration of President Moon Jae In, a progressive who has long supported inter-Korean unity, hoped this latest rapprochement would create similarly warm feelings.

Instead, a survey found that more than 72 per cent of South Korean adults overall - and more than 82 per cent of those in their 20s and 30s - were not enthusiastic about the hockey team.

More than 54,000 people signed a petition opposing it, and many expressed anger that some South Korean players would cede their positions to North Koreans.

"I am taken aback," said former South Korean foreign minister Kim Sung Hwan. "Young people seem to think of North Korea as strangers who barge into their party bringing with them nothing but empty spoons."

Such pushback would have been expected from conservatives, who have long been suspicious of efforts to engage the North. But younger South Koreans tend to be politically progressive and supportive of Mr Moon on other issues.

Analysts said that years of increasingly provocative nuclear and missile tests have darkened South Korean perceptions of the North and its young leader Kim Jong Un. Actions such as Mr Kim's executions of his own uncle and his half brother have also made the regime look brutal and grotesque.

"We know that this sudden shift in mood could be confusing for people, especially given how unsettled they were over the North's missile tests up until just a month ago," said President Moon's spokesman Yoon Young Chan. "But the Pyeongchang Olympics can go beyond South-North reconciliation and provide clues to easing tensions and building peace on the Korean Peninsula."

Analysts say a key turning point in attitudes towards the North came in 2010, when a South Korean naval ship was sunk by an apparent North Korean torpedo attack, killing 46 sailors, and North Korea launched a rocket barrage on a South Korean island that killed four people, including two civilians. These were formative events for young South Koreans, these analysts say.

Key members of Mr Moon's presidential office and governing party are progressives in their 50s, who went to college in the 1980s.

Then, campuses were rife with anti-American activism, partly driven by resentment over the division of the Korean Peninsula after World War II. Students defied authorities by sending a "unification envoy" to the World Festival of Youth and Students, alternative games that North Korea held in Pyongyang in 1989 to counter the previous year's Summer Olympics in Seoul.

Progressives in that era believed in a peaceful process of reunification, built on the expansion of economic and social exchanges. Today, many of that generation see the North's nuclear weapons programme as a desperate attempt to protect itself from the United States and the South, with which it is still technically at war.

Reunification is also a personal matter for Mr Moon, 65, who was born in a refugee camp after his parents fled their native North Korea during the 1950-53 Korean War.

"If Korea reunified, the first thing I would do is to take my mother's hand and visit her hometown," he said during last year's election campaign.

The assumption that the South and North belong together is shared by many South Korean conservatives, though from a very different point of view. They tend to call for the South liberating the North from the Kim family's rule, by force if necessary.

The horrors of the Korean War, which killed millions, bound older South Koreans together. Many still grow teary-eyed on those occasions when the rival governments allow select groups of ageing citizens to meet relatives from the other side after decades of separation.

Younger South Koreans do not share the pain caused by the peninsula's divide, or the inclination to see North Koreans as long-lost brethren. Last year's survey by the unification institute found that while more than 47 per cent of respondents in their 60s and older said the two Koreas must reunify "because they belong to the same nation", less than 21 per cent of respondents in their 20s said so.

Warier views of the North are not limited to the young. Many South Korean conservatives, young and old, embrace the view that the North is building nuclear-tipped intercontinental missiles to drive a wedge between it and the US, its longtime protector.

They fear that if Mr Kim thinks the threat of a nuclear strike on the mainland US will keep the Americans from intervening, he may try to take over the South, the dream that his grandfather, Mr Kim Il Sung, the North's founding leader, failed to achieve during the Korean War.

Last Thursday (Jan 25), North Korean state media called on "all Koreans at home and abroad" to support moves toward reunification and eliminate obstacles created by "outside forces", a reference to the US.

Many South Koreans are relieved that North Korea is joining the Olympics, because it is less likely to conduct a major weapons test while its own athletes are competing in Pyeongchang. But they remain deeply sceptical about Mr Kim's sudden peace offensive.

In a town near the Olympic venues, restaurant worker Kang Hee Du, 54, wondered how the Koreas could possibly reunify when they have drifted so far apart, economically and ideologically. "It would be nothing but chaotic," he said.

But retired car-component maker Choi Sang Hwan, 73, lamented the new attitude.

"Our generation knows how tragic war can be; it can take everything away," said Mr Choi, who is also an Olympic volunteer. "It's our duty to let our future generations live peacefully in a unified Korea."