Seoul: After South Korea's parliament impeached President Yoon Suk Yeol on Saturday, Prime Minister Han Duck-soo has stepped in as acting president. A seasoned technocrat, Han’s extensive experience and reputation for level-headedness could prove invaluable in this high-stakes role.

Following the impeachment vote triggered by Yoon’s brief attempt to impose martial law, Yoon has been suspended from exercising his presidential powers. According to the constitution, the prime minister assumes the role of acting president in such cases. Han, 75, brings with him over three decades of leadership experience across various governmental roles, having served under five different presidents—both conservative and liberal—making him a rare figure in a politically polarized country.

Han’s immediate challenge will be to navigate South Korea’s most serious political crisis in forty years, all while addressing threats from a nuclear-armed North Korea and managing a faltering domestic economy. His time as acting president could also be jeopardized by ongoing criminal investigations into his involvement in the martial law decision.

A Harvard-trained economist, Han’s career spans a range of critical roles, including ambassador to the U.S., finance minister, trade minister, presidential secretary for policy coordination, and head of various think tanks. He is known for his pragmatic approach to governance and his ability to rise above political factions.

Since Yoon’s presidency began in 2022, Han has served as prime minister for a second time, after previously holding the post under President Roh Moo-hyun in 2007-2008. When appointing Han, Yoon praised his non-partisan reputation and broad expertise. "He has served in key posts through recognition of his skills and expertise, regardless of political factions," Yoon remarked.

Han's tenure includes significant experience in international diplomacy and economic policy, notably in his role as South Korea’s ambassador to the U.S. in 2009, where he played a pivotal part in securing congressional approval for the U.S.-South Korea Free Trade Agreement. Fluent in English, Han’s work with the U.S. helped cement his standing as an influential figure in both domestic and global affairs.

Despite his long career in public service, Han has managed to avoid being closely associated with any political party, earning him respect across the political spectrum. A former high-ranking government official described him as "a civil servant through and through, not bound by political colours, despite working under five different presidents."

Han’s role as acting president could last for months, depending on the Constitutional Court’s decision regarding Yoon’s impeachment. Should Yoon be removed, a snap election would be required within 60 days, and Han would continue to hold the position until then.

However, the Democratic Party, the primary opposition, has filed a complaint against Han, arguing that he should be investigated for failing to block Yoon’s martial law attempt. Should parliament decide to impeach Han, the finance minister would be next in line to serve as acting president.

While the South Korean Constitution is vague on the specific powers of the prime minister in such a situation, most legal scholars argue that Han can only exercise enough authority to prevent a breakdown of state functions, while others contend that he could, in theory, wield full presidential powers until a formal resolution is reached.