To be in Seoul on the night of 3 December must have been deeply unsettling. At least, for a brief moment.

According to President Yoon Suk Yeol of South Korea, the nation was under some unspecified form of attack from North Korea and he had no choice but to declare martial law. For many in this East Asian nation of 52 million people, it was the most concerning moment in recent history… up until 190 South Korean politicians managed to clamber over the walls of parliament to vote down Yoon’s proclamation.

For locals and those who are familiar with South Korea’s modern history, the events were something of a blast from the past, one of the Greatest Hits from the country’s political back catalogue. Though it was the first time martial law had been imposed for over four decades, Yoon’s rhetoric was redolent of that used by the right wing military dictators of the 1960s and 70s in order – depending on your viewpoint – to maintain the necessary state of preparedness for invasion, or to keep everyone working relentlessly to maintain the accumulation of wealth and power for the political and corporate elites.

In the early 1950s, Korea was torn apart by war, the South was raised from the rubble by an economically successful dictator, Park Chung Hee, and became a democracy in 1987. Since then, real power has lain largely with the corporations, or ‘chaebols’, which emerged from Park’s economic strategy – most famously Hyundai, Samsung, LG, Lotte and Hanjin. Their family owners have always enjoyed ‘close’ relations with the country’s rulers.

There is not enough space here to detail the corruption associated with the role and practices of the chaebols, most of which are now in the hands of the third generations of the same families. As long as their grip on power remains, South Korea will struggle to address its serious social inequalities and demographic challenges, not to mention its political volatility: four of the nation’s post-democracy presidents have ended up in prison and one committed suicide while under investigation for corruption.

Meanwhile, Yoon blamed and sacked his defence minister; and there are attempts by the opposition to impeach him. By the time you read this, I am guessing he will be under house arrest, and the long procedure to indict this former prosecutor will begin. As I write, a reported 70 per cent of South Koreans are in favour of Yoon’s impeachment, the unions are already moving against him and public protests are under way in chilly Seoul.

This may sound bleak, but there are positive aspects of Yoon’s apparently imminent political demise. When I spent some time in South Korea following its last major upheaval in 2017 – when the then president, the daughter of the dictator Park Chung Hee, Park Geun-hye was removed from office and replaced by left-winger, Moon Jae-in – I witnessed an exceptionally potent, people-led democracy in action. Hundreds of thousands of Koreans took to the streets in an orderly, organised fashion (cleaning up after themselves, naturally), for months, to protest at Park’s blatant, chaebol-linked corruption.

Today, Korea’s neighbours, the Japanese, will doubtless be rolling their eyes at what they see as characteristically impetuous and emotional behaviour by their old foe. Yet, in recent years, South Korea has become not only a lighthouse in the region for robust, people-led democracy, but also for its cultural dynamism and attempts at modernisation. Certainly, the Koreans have far outshone the passive Japanese when it comes to imposing their will on their leaders.

The volatility the Japanese scorn in their neighbours, I view as a positive force. South Korea has a population who vote with their feet and protest peacefully; they have not only changed the course of their governments but have brought them down.

South Koreans seem well-placed to withstand an errant leadership’s inept attempts to block parliamentary process. During Yoon’s (very) brief period of martial law, South Korea’s newspapers continued to report what was happening, ignoring the supposed ban on coverage, and MPs within Yoon’s own party openly defied him.

Why did he take such an extreme, provocative and chronically ill-judged measure as to impose martial law? As with most presidents in South Korea’s recent history, corruption accusations stalk Yoon and his wife, Kim Keon-hee. Even by the standards of his predecessors, he is extremely unpopular with record low approval ratings of 19 per cent. He also isn’t much of a politician; he is an outsider, with poor judgement when it comes to advisors.

Perhaps South Korea will swing to the left once again, as it seems to do every other election or so, and a kind of jerky equilibrium will be maintained, at least regarding relations to the North. The right wing withdraws and grows hawkish, the left makes gestures towards amity. The country goes from bad cop to good cop in terms of its relations with the Kim dynasty.

But things are not quite so binary these days. In 2017, President Yoon helped bring down the last conservative president, Park Geun-hye. Meanwhile, opposition leader Lee Jae-myung, who only narrowly lost the election to Yoon in 2022, has himself been tainted by corruption charges connected to a dodgy land deal during his time as mayor of the north western city of Seongnam, close to Seoul.

Like the previous Democratic Party president, Moon, Lee is a former student activist and human rights lawyer, an idealist who has a typically hard-bitten life story of growing up during the dictatorship era. But he is reassuringly vague when it comes to what measures he would actually take with regard to North Korea.

As in so many aspects of global politics and economics, the great variable at the moment is the US. During his last term, Trump dabbled in the Korean issue, to little effect. This time, the great concern is a more significant withdrawal of US support for the South. That really is unsettling.