South Korean President Yoon Suk Yeol faces mounting calls for resignation or impeachment after declaring martial law late Tuesday, only to reverse the decision hours later. The controversial move has plunged Asia’s fourth-largest economy into a political crisis, triggering mass protests and political fallout.

President Yoon justified the imposition of martial law in a televised address, citing threats from nuclear-armed North Korea and “pro-North anti-state forces.” He argued the measure was necessary to protect the nation’s constitutional order but failed to provide concrete evidence of such threats.

The declaration, which included banning political activity, media censorship, and deploying armed troops to seize control of the National Assembly, sparked outrage among lawmakers.

Chaos ensued as troops tried to seize control of the parliament building. Parliamentary aides barricaded themselves and sprayed fire extinguishers to push them back, while protesters scuffled with police outside.

A worker removes a piece of furniture that was used for barricading when military forces broke into the National Assembly building after South Korean President Yoon Suk Yeol declared martial law, which was reversed hours later, in Seoul, South Korea, December 4, 2024. REUTERS/Kim Hong-Ji TPX IMAGES OF THE DAY

South Korea has a fraught history with martial law, with more than a dozen declarations since its establishment as a republic in 1948. The last significant instance occurred in 1980 when martial law was used to suppress pro-democracy protests.

A woman reacts among police officers outside the National Assembly, after South Korean President Yoon Suk Yeol declared martial law, in Seoul, South Korea, December 4, 2024. REUTERS/Kim Soo-hyeon TPX IMAGES OF THE DAY

Parliament swiftly defied the decree, with all 190 lawmakers present voting unanimously to demand its repeal, including members of Yoon’s ruling People Power Party.

Public sentiment remains deeply critical of Yoon, whose approval ratings have languished at around 20% for months. Protests have intensified, with the Korean Confederation of Trade Unions calling for a nationwide strike until Yoon resigns.

Internationally, Yoon’s declaration prompted cancellations of planned diplomatic engagements. Sweden’s prime minister postponed a visit to South Korea, while Japan’s parliamentary delegation called off a mid-December trip. Joint military drills with the U.S. were also postponed.

Protesters from conservative groups attend a rally supporting South Korean President Yoon Suk Yeol and denouncing opposition party’s politicians after the President’s surprise declaration of the martial law last night, in Seoul, South Korea, December 4, 2024. REUTERS/Kim Kyung-Hoon

U.S. Secretary of State Antony Blinken welcomed the reversal, emphasizing the importance of resolving political disputes peacefully and within the rule of law.

The fallout extended beyond politics. Financial markets reacted sharply, with South Korean stocks dropping around 2% and the won plunging to a two-year low before stabilizing after suspected intervention by authorities. The government pledged to inject unlimited liquidity into markets if needed to stabilize the economy.

The opposition Democratic Party, backed by five other parties, condemned Yoon’s actions as a severe overreach. Senior Democratic Party lawmaker Park Chan-dae declared, “It was clearly revealed to the entire nation that President Yoon could no longer run the country normally. He should step down.”

Protesters from conservative groups attend a rally supporting South Korean President Yoon Suk Yeol and denouncing opposition party’s politicians after the President’s surprise declaration of the martial law last night, which was reversed hours later in Seoul, South Korea, December 4, 2024. REUTERS/Kim Kyung-Hoon

The opposition announced plans to introduce an impeachment bill on Wednesday, with a vote likely on December 6 or 7. Impeachment would require a two-thirds majority in the 300-member National Assembly.

If passed, the case would proceed to South Korea’s Constitutional Court, where at least six of nine justices would need to confirm the motion to remove Yoon from office.

If Yoon is impeached or resigns, Prime Minister Han Duck-soo would assume leadership until a new election is held within 60 days.