The number four is viewed with deep suspicion in many East Asian cultures, more so than the number 13 in the West – and South Korea is no exception. For supporters of Yoon Suk Yeol, the 13^th South Korean president, the fourth day of the fourth month of 2025 would only confirm such superstitions: it will be forever remembered as the day when Yoon was ousted from power. For the young democracy of South Korea, which only transitioned to democratic government in 1987, the political polarisation that has characterised its society and catalysed the untimely destinies of many of its past presidents looks set to linger.

Yet amid domestic and international change, Asia’s fourth largest economy cannot sit idly by. South Korea must ensure that its relationship with the United States does not deteriorate further and, closer to home, that the heightened threat from North Korea is not ignored.

Given the more than three-month wait for the verdict to be announced, it was somewhat surprising that all eight justices on South Korea’s Constitutional Court – which remains one-judge short – unanimously agreed to remove Yoon from power. The final judgement, which deemed Yoon to have violated the country’s constitution, upheld December’s decision to impeach the president.

While Article 77 of the South Korean Constitution underscores how it is not illegal for the South Korean president to declare martial law, any such declaration must be made during ‘time of war, armed conflict or similar national emergency’. As the acting president of the court, Moon Hyung-bae, highlighted: ‘political gridlock or suspicions of election fraud’ – two of the grounds upon which Yoon justified his decision – ‘should be resolved through political, institutional and judicial means, and cannot be resolved by mobilising military forces’.

For all the shock of December’s bizarre martial law declaration, its short-lived nature and the court’s subsequent actions highlight how South Korea remains a durable democracy, albeit a sharply divided one. As the country enters its interregnum, and as the presidential race gains momentum, internecine conflict within and across party lines will likely continue.

While a general election must happen before 3 June, history tells us that a power vacuum increases the propensity for things to go wrong.

The frontrunner opposition candidate for the left-leaning, progressive Democratic Party is likely to be the controversial 61-year-old Lee Jae-myung. Lee is an old hat. He was Yoon’s main opponent in 2022’s ‘election of unlikeables’ and, akin to his then-opponent, has been long-mired in personal scandal. For all his attempts to moderate his views, a victory by Lee would see a considerable shift in South Korea’s foreign policy. Taking a different path to the currently ruling People Power Party, he would probably tilt away from the United States and Japan, and adopt a more conciliatory approach towards China and North Korea.

For the ruling party, no favourite has yet emerged. One possible contender is Han Dong-hoon, a former justice minister in Yoon’s first cabinet, who underwent a volte-face from being one of Yoon’s closest aides to becoming a vociferous supporter of his dismissal. Another potential candidate is the current mayor of Seoul, Oh Se-hoon, who previously stressed how a South Korean president must ‘respect the limits of their knowledge’ and ‘understand the challenges of the future’.

Yet in addition to recognising the need to address the challenges of the future, South Korea must not lose sight of the challenges of today, not least the ever-changing geopolitical environment beyond its borders.

Soon after Trump’s election victory in November 2024, Yoon Suk Yeol was seen practising his golf swing, in readiness for a future tête-à-tête with the 47th US president. Now, a president-less South Korea must simultaneously navigate political drama at home and the choppy waters of international affairs. Seoul arguably anticipated an incoming Trump administration’s likely actions when, weeks before US election day, South Korea agreed to increase the cost of stationing American forces on the Korean Peninsula by 8.3 per cent as part of the US-Republic of Korea Special Measures Agreement, effective from 2026.

Yet the Trump administration’s recent imposition of 25 per cent tariffs on South Korean exports to the United States – including automobiles and semiconductors – will likely strike Seoul hard and become a core focal point for any election candidate. Although Acting President Han Duck-soo anxiously initiated calls to negotiate with the US following these tariffs, little can be achieved in the two month pre-election period, after which he will likely be out of office.

For all the idiosyncrasies of Trump and his administration, South Korea would be unwise to jeopardise its relations with the United States, even if Washington’s current rhetoric, where Seoul is seen as more of a burden than a blessing, leaves a bitter taste in the mouths of ruling South Korean officials.

Closer to the Korean peninsula, a key past, present, and future challenge continues to haunt the South – North Korea. The totalitarian state has leveraged the political chaos in South Korea over the past few months, decrying the now-ousted president as a ‘fascist dictator’ and continuing its time-old trope of deriding South Korea as a US ‘puppet state’. In response to Friday’s verdict, North Korean state media did not issue any response of its own, merely mentioning how foreign news outlets, including Reuters and the Guardian, had reported how Yoon’s declaration of martial law had caused the ‘worst political crisis’ in South Korea. Such an approach is a common aspect of North Korea’s strategy: Pyongyang wants to signal to domestic and external audiences that criticisms of its southern enemy do not just emanate from within, but also from the West.

Given its history of delinquent behaviour, Pyongyang is likely to exploit the power vacuum within its primary foe to escalate its provocations towards the West. After all, over the past four years, North Korea has demonstrated little to no interest in talks with its neighbour. Any such interest plummeted further after January 2024, when Kim Jong Un abandoned the country’s long-standing policy of reunifying the Korean peninsula under the North’s control.

Amid ongoing testing of improved nuclear and missile capabilities, South Korea has also been a victim of bizarre North Korean grey-zone warfare tactics. The past year has seen the frequent deployment of balloons carrying excrement and rubbish across the inter-Korean border, with many disbursements landing in Seoul. Making matters worse is North Korea’s heightened co-operation with Russia. Nearly 14,000 North Korean soldiers have hitherto been deployed to the Kursk region to support Russian troops in Putin’s war against Ukraine; all the while Seoul refrains from providing direct lethal assistance to Kyiv.

The political philosopher Michael Oakeshott once described political activity as characterised by ‘neither starting-place nor appointed destination’. Only time will tell as to what South Korea’s appointed destination will look like, and its consequences for Seoul’s ties with Washington, Pyongyang, Tokyo, and Beijing.

In an article that he penned for Foreign Affairs a month prior to his election in March 2022, the now-former President Yoon Suk Yeol called on South Korea ‘to step up’. Doing so will not be easy, at a time when the country lacks what its needs the most, namely a leader to steer the ship against the turbulent headwinds of inter-Korean tensions, uncertainties in the US-South Korea alliance, and menacing threats from North Korea and China.

Yet, to waste the next two months being embroiled solely in domestic political tumult would be a very unwise move indeed.