SEOUL (THE KOREA HERALD/ASIA NEWS NETWORK) - To South Koreans, North Korea has never been a foreign country.

Despite the war six decades ago and occasional military conflicts with it thereafter, North Koreans were always "brethren" to those in the South who share the same history, culture and language.

Even at the height of inter-Korean tensions, there were always people in the South who sympathised with the sufferings of those across the border.

This complex sentiment towards North Korea is now giving way to a more hawkish one, as the communist regime, under the young third-generation leader Kim Jong Un, has been stepping up military provocations.

Many interviewed by The Korea Herald expressed anger and frustration at how a peace-loving nation, which has abided by rules and stayed away from nuclear weapons, has become more vulnerable, while the defiant North made headway towards becoming a formidable military power.

"Now that North Korea appears to be equipped with nuclear arms, I believe we also need to have the same power to stop the North," office worker Yu Young Eun told The Korea Herald. "We are the weakest country here now, and I think we also need to let neighbouring and related countries know that we should be in charge of the North Korean issues."

A recent poll by Gallup Korea, conducted from Sept 5 - after the Sept 3 nuclear weapons test by the North - shows a clear sign of hardening attitudes among South Koreans.

Of 1,004 respondents, 76 per cent considered the sixth atomic detonation as a threat to security, while only 20 per cent answered it was not a threat. But when asked if they thought the North would initiate a war, only 37 per cent answered it was possible, while 58 per cent responded that that was little to no chance of such an outcome.

However, the poll showed that more people want stronger measures to pressure the North. In the poll, 60 per cent approved of South Korea possessing nuclear arms while 35 per cent opposed the idea.

US tactical nuclear weapons were withdrawn from the Korean Peninsula in 1991, when the two Koreas signed an agreement on denuclearisation, non-aggression and reconciliation.

While the idea is mainly pushed by conservatives that pursue tougher policies against the North, liberal voters also appeared to be in support of such armament, the data showed. Of the 353 respondents who viewed themselves as liberals, 47 per cent approved of stationing nuclear weapons here, while 48 per cent of the group opposed the idea.

What is more surprising, perhaps, is that more South Koreans even said that humanitarian aid should be cut if the North does not give up its nuclear programme.

In 2013, a Gallup poll showed that 47 per cent of South Koreans said that humanitarian aid should continue even if North Korea continues its nuclear programme.

In the recent poll, the figure dropped to 32 per cent, while the proportion of South Koreans opposed to the idea rose to 65 per cent.

Left-leaning respondents were also sceptical of offering any kind of humanitarian aid, with 52 per cent of them calling for a halt.

Experts viewed that the gradual change in public sentiment reflects disappointment toward North Korea, which South Koreans once considered their "northern brother" after the painful separation.

"The liberals, who were thought to be relatively more friendly towards the North, are now turning their backs, as they see their northern neighbour is not so brotherly anymore," a Gallup Korea researcher said. "Despite President Moon Jae In's suggestions for dialogue and peaceful approaches, the North is not taking the kindness and has only become a threat."

The researcher, who declined to reveal his name, also explained that there have been actual cases of attacks against South Korea. "One of the prime cases would be North Korea's attack on Yeongpyeong Island. There, Koreans witnessed that, however we treat them, they can actually attack us," he said.

In November 2010, North Korea shelled the island located 80km west of Incheon, killing two South Korean Marines and two civilians, and wounding 18.

Another reason behind the shift in attitude may be that South Koreans are not happy to see another dictator, Mr Kim Jong Un, inheriting power from his father and reinforcing his authority in such provocative ways, he added.

"The way the communist state continues to show enmity towards the international society is childish. It does not know what is good for them, and we see that our kindness is not returned with kindness but ignorance and hostility," said 26-year-old student Yang Jin Young .

Other members of the public say that the apparent irrationality of the North Korean leader seems to be the biggest threat.

"I heard Kim is very impulsive and I believe that he may really launch a nuclear bomb. We should never let that happen, and I wish all concerned nations would just ignore North Korea," said office worker Kim Su Jin, 30.

There also seems to be concerns about the changes in the way Pyongyang deals with Seoul and its allies.

"What the North is demanding from the South and the international society has changed. In the past, it was just financial aid to its poor economy, but now it is calling for the ouster of the US armed forces in South Korea," said business owner Yeo Young Soo, 60. "What is more serious is that the North is now ignoring the South."