Why did South Korea's president declare martial law?

• South Korea's president, Yoon Suk Yeol, declared martial law in a shock address.
• The move empowered the army to shut down political activity, enraging the opposition.
• Yoon was struggling to pass legislation and chafed at measures to rein in his presidency.

South Korea's president, Yoon Suk Yeol, on Tuesday invoked martial law, a stunning move that threw the nation into turmoil.

It's the first declaration of martial law — enabling temporary rule by the military — since the country's democratization in 1987. The last time that a South Korean leader declared martial law was in 1979 following the assassination of the president. It has never been declared since South Korea became a parliamentary democracy.

Yoon's late-night announcement prompted protests outside parliament, with some lawmakers trying to climb its walls, as well as intense criticism of Yoon for short-circuiting the country's democracy.

South Korea's parliament voted unanimously to block the president's decree, declaring the shocking move invalid, but martial law remains in effect.

Why now?

Yoon indicated the move was necessary to counter North Korea, but the move appears political.

In a television address, Yoon spoke of "anti-state forces," saying martial law was necessary to eliminate them quickly and "normalize the country."

He criticized the country's opposition politicians, a response to a series of political setbacks that frustrated his agenda.

Yoon has suffered from low approval ratings this year and has been described as a "lame-duck president", holding the nation's highest office but without a majority in its legislature.

His conservative People Power Party lost a general election in April, in which the rival Democratic Party of Korea took 175 of the 300 seats in the National Assembly.

The opposition majority in parliament last week voted to cut almost $3 billion from Yoon's 2025 budget, undermining his rule.

The opposition has also tried to impeach three top prosecutors, the Associated Press reported.

Meanwhile, Yoon has been involved in several corruption scandals, including one in which his wife is accused of manipulating stocks.

What does it mean?

Invoking martial law means parliamentary activity is banned, according to the country's government-funded Yonhap news agency. Anyone who violates the rules can be arrested without a warrant.

The semi-official South Korean news agency also said that media and publishers fall under the control of the South Korean military.

Doctors, who have been striking for months in protest of the government's plan to increase medical school admissions, are compelled to return to work within 48 hours.

Yoon didn't say how long he intended to maintain martial law.

What has been the reaction?

South Korea is a key US ally in the Indo-Pacific region and home to roughly 24,000 American service members, as well as numerous civilian workers and dependents.

Amid the chaos, US Ambassador to South Korea Philip Goldberg said the embassy and State Department "are closely tracking President Yoon's recent declaration of martial law," adding that the "situation is fluid."

The unexpected move, which is said to have caught the Biden administration by surprise, also alienated members of Yoon's own party.

Han Dong-hoon, the leader of the ruling People Power Party, said imposing martial law was "wrong" and that he would "stop it with the people." South Korea's main opposition leader, Lee Jae-myung, described the move as unconstitutional.

Yonhap said politicians from Lee's party had been asked to congregate outside the country's National Assembly.

Hours after Yoon declared martial law, live TV showed South Korea's parliament passing a motion requiring the law to be lifted. Whether Yoon will comply with the vote, as the constitution requires, remains to be seen. There have been reports, however, that South Korean military personnel have withdrawn from parliament.

The US National Security Council said on Monday: "The administration is in contact with the [Korean] government and is monitoring the situation closely."

The value of the South Korean won fell to its lowest level since October 2022 on Tuesday. Additionally, South Korean stocks, such as the iShares MSCI South Korea ETF and shares of companies like Coupang, KB Financial Group, and POSCO Holdings, dropped significantly as martial law went into effect.

The country's stock-market operator said it had yet to decide whether to open for trading on Wednesday, according to The Wall Street Journal.