South Korean President Yoon Suk Yeol’s Dec. 3 martial law declaration—the first in 45 years—has sparked accusations of constitutional violations and ignited debates over impeachment and potential insurrection charges. Critics argue the move flouts legal norms and raises unprecedented challenges for the sitting president.

The South Korean Constitution permits martial law only in cases of war, armed conflict, or similar national emergencies. Article 77 states, “The President may proclaim martial law under the conditions as prescribed by Act.” The Martial Law Act grants military commanders extraordinary powers during such periods, allowing them to restrict freedoms like speech, assembly, and movement, provided these measures are publicly announced in advance.

President Yoon justified the declaration by citing 22 impeachment motions against government officials and opposition-led budget cuts of 4.1 trillion won ($3.2 billion) for 2025. However, legal scholars argue these reasons fall far short of the “national emergency” threshold required to invoke martial law.

Martial law troops break through a window to enter the main National Assembly building in the early hours of Dec. 4, 2024. Aides barricaded hallways with chairs and desks and used fire extinguishers to hold them off, leading to confrontations throughout the building./Newsis

“Impeachment or budget issues are political matters to be resolved through dialogue,” said Jung Hyung-keun, a professor at Kyunghee University Law School. “Using military force to address these issues reflects an anti-constitutional mindset.”

Kim Hae-won, a professor at Pusan National University Law School, noted that most impeachment cases had already been referred to the Constitutional Court, and budget negotiations between the ruling and opposition parties were still ongoing. “Even if deemed critical, invoking martial law to use military force was entirely inappropriate,” Kim said.

However, procedural lapses in the declaration are adding to the controversy. While President Yoon sought deliberation by the State Council, as required under the Martial Law Act, he failed to notify the National Assembly “without delay,” as mandated by both the Constitution and the Martial Law Act. National Assembly Speaker Woo Won-shik confirmed no notification had been received. “We learned about the declaration through the news,” said Choo Kyung-ho, floor leader of the People’s Power Party.

Given these concerns, many argue Yoon could face impeachment. Under South Korean law, impeachment requires a majority vote in the National Assembly, followed by approval from two-thirds of its 300 members. If passed, the president would be suspended from office pending a decision by the Constitutional Court, which could ultimately remove him from office.

Acting Chief Justice of the Constitutional Court Moon Hyung-bae (top left, clockwise), Justices Kim Hyung-du, Cheong Hyung-sik, Lee Mi-son, Jung Jung-mi, and Kim Bok-hyeong arrive at the Constitutional Court in Seoul on Dec. 5, 2024. Opposition parties, including the Democratic Party of Korea, filed an impeachment motion against President Yoon Suk-yeol on Dec. 4, citing the unconstitutional declaration of martial law. A vote could take place as early as Dec. 6 or 7. If passed with the support of two-thirds of the 300-member National Assembly, the case will move to the Constitutional Court. Under Article 65 of the Constitution, Yoon’s presidential powers would be suspended immediately pending the court’s ruling./News1

The controversy deepened on Dec. 4, when opposition parties and civic groups announced plans to file criminal complaints against Yoon for insurrection. They allege the president violated the Constitution by mobilizing military forces to paralyze the National Assembly.

South Korea’s Criminal Act defines insurrection as actions aimed at eliminating constitutional functions or disrupting the operations of constitutional institutions, punishable by death or life imprisonment.

Legal opinions on whether Yoon’s actions meet the definition of insurrection are divided. Some point to the first martial law proclamation, which banned legislative and political activities while deploying troops to the National Assembly. “The deployment of troops to disrupt parliamentary functions and the prohibition of political activity could be deemed unconstitutional,” said Kim Seon-teak, a professor at Korea University School of Law. Hoh Il-tae, an honorary professor at Dong-a University, added, “If the military’s deployment is interpreted as an attempt to seize control of the National Assembly, insurrection charges could be considered.”

Others, however, argue against such charges. Kim Sang-kyum, an honorary professor at Dongguk University, said insurrection requires both intent and a political motive to overthrow the constitutional order. “It’s unclear if President Yoon had such intent,” he said. “The situation did not escalate to the level of fully blocking parliamentary operations.”

Bae Bo-yoon, a former Constitutional Court spokesperson, said the situation may not meet the criteria for a “national emergency,” but military entry into the National Assembly to maintain order does not necessarily imply insurrection.

While insurrection charges could result in the prosecution of a sitting president, questions remain over jurisdiction. Prosecutors claim insurrection falls outside their direct investigative authority following legal reforms, while the Corruption Investigation Office for High-ranking Officials has stated that such cases are not within its scope.