Koh Jae-hak can still vividly remember when he saw soldiers gunning down a group of young women in cold blood.

It was April 1960. Students had launched protests calling for the resignation of the dictatorial president Syngman Rhee. Mr Koh was working in a government building when he looked out of the window and saw protesters clashing with police.

“There were demonstrations from various universities, and they all gathered in front… that’s when shots were fired,” the 87-year-old said. Days later, martial law was declared.

South Korea is widely considered a peaceful beacon of democracy in Asia, but that wasn’t always the case. This is a country that saw 16 bouts of martial law during its first four decades ruled largely by dictators.

It is why democracy is now deeply treasured by South Koreans as a hard-won right. It is also why President Yoon Suk-yeol’s declaration of martial law this week – the first to happen in 45 years and during democratic rule – was particularly triggering and prompted such a visceral response.

Almost immediately, lawmakers jumped out of bed and rushed to the national assembly, clambering over fences to reverse martial law.

Hundreds of ordinary citizens gathered to hold back troops who had been ordered to throw out MPs.

Some soldiers, apparently unwilling to carry out their orders, reportedly dragged their feet in clearing the crowd and entering the building.

When Yoon declared martial law on Tuesday night, he said it was necessary to get rid of “pro-North anti-state” forces. Initially, it caused confusion with some South Koreans who believed there was a genuine threat from the North.

But as they continued watching Yoon’s televised announcement, many grew sceptical. He gave no evidence of such forces at work, nor explained who they were. As Yoon had previously used similar language to describe the opposition that had been stymying his reforms, the public concluded he was actually trying to crush his political foes.

Previous periods of martial law had also been justified by leaders as necessary to stabilise the country, and sometimes stamp out what they alleged were communist subversives planted by North Korea.

They curtailed freedom of press and freedom of movement. Night curfews and arrests were common.

Violent clashes sometimes took place, most indelibly in 1980, when then President Chun Doo-hwan extended martial law to deal with student protesters calling for democracy in the southern city of Gwangju. A brutal military crackdown was launched, and it has since been labelled a massacre – while the official death toll is 193, some experts believe hundreds more died.

South Korea eventually transitioned to democracy in 1988, when the government held its first free and fair presidential election following mounting public pressure. But the preceding decades had permanently and profoundly shaped the nation’s consciousness.

“Most Koreans have trauma, deep trauma, about martial law,” said Kelly Kim, 53, an environmental activist. “We don’t want to repeat the same thing over and over.”

Ms Kim was a young child when martial law was last in place and has little memory of it. Still, she shudders at the thought of it returning.

“The government would control all the media, our normal activities. I’m working in civil society, so all our activities, like criticising the government, would not be possible under the martial law. So that’s really horrible.”

The freedoms afforded by democracy have not just led to a thriving civil society.

In the more than 35 years since that first democratic election, South Korea’s creative industries have flourished, with its dramas, TV shows, music and literature becoming world famous. Those creative industries have turned their own lenses onto the country’s past, bringing history to life for those too young to remember.

The country has seen a proliferation of shows about its dictatorship past, immortalising incidents such as the Gwangju uprising in popular culture.

Some were blockbusters featuring South Korea’s biggest stars, such as last year’s 12.12 The Day, a historical drama starring popular actor Hwang Jung-min. The movie depicts the political chaos that took place in 1979 as martial law was declared following the assassination of then president Park Chung-hee.

“As soon as I saw the images [of Yoon’s declaration of martial law], it reminded me of that movie… it made me question, are we about to repeat that history now?” said Marina Kang, a 37-year-old web designer.

“Korea’s got a wealth of visual representational works [of that era] in films and documentaries. Though we only have indirect experience of the horrific past through these works… that still makes me feel very strongly that such events should not happen again.”

Among younger citizens, there is a sense of disbelief that it could have returned. Despite never knowing life under martial law, they have been taught by their parents and older relatives to fear it.

“At first [when I heard Yoon’s announcement], I was excited at the thought of getting a day off from school. But that joy was fleeting, and I was overwhelmed by the fear of daily life collapsing. I couldn’t sleep,” said 15-year-old Kwon Hoo.

“My father was concerned that under martial law, he wouldn’t be able to stay out late even though his work required him to… when he heard the news about the possibility of a curfew being imposed again, he started swearing while watching the news.”

Not all South Koreans feel this way about their past.

“The vast majority of Koreans appreciate democracy enormously and regret the authoritarianism of the post-war period,” said Mason Richey, associate professor of international politics at Hankuk University of Foreign Studies in Seoul.

But, he added, “the country remains very divided regarding numerous aspects of the authoritarian past, notably how justified certain repressive measures were in order to prevent communist subversion.”

There is the view among a significant portion of the population, especially among older folk, that martial law was necessary in the past for stability and democracy.

“Back then, it was a time defined by ideological warfare between democracy and communist socialism,” said Kang Hyo-san, 83. He was sitting next to his friend Mr Koh in a cafe at Gwanghwamun, Seoul’s main square and focal point for the city’s protest rallies.

The competing ideologies would lead to clashes and “when the military intervened, the situation would stabilise… it was a process to restore order and properly establish free democracy.

“Given the circumstances, we couldn’t help but view it positively,” he said, adding that he felt each period of martial law left the country in a more “favourable” position. Martial law in South Korea “fundamentally differed” from other nations, where it “wasn’t about killing people or senseless violence”, he insisted.

But this time, it’s different. Both octogenarians felt that Yoon’s declaration of martial law was unacceptable. “Even though we’ve experienced martial law many times throughout our lives, this time there’s no justification for its declaration,” said Mr Koh.

Like them, Ms Kim, the environmental activist, was glad Yoon did not succeed and democracy prevailed in the end. “Because we fought so hard to get it, right? We don’t want to lose it again.

“Without democracy and freedom of living, what is life?”