For Yoon Suk Yeol, the unpopular president of South Korea, things appeared to worsen with each passing day. Thousands of doctors had been on strike for almost a year to resist his health care reforms. The opposition in Parliament repeatedly pushed for investigations into his wife, as well as the impeachment of his cabinet members, accusing them of corruption and abuse of power. And the lawmakers blocked many of Mr. Yoon’s bills and political appointments.
On Tuesday night, Mr. Yoon took a desperate measure, his boldest political gamble that he said was driven by frustration and crisis. In a surprise, nationally televised address, he declared martial law, the first time in the country in decades. The move banned all political activities, civil gatherings and “fake news” in what he called an attempt to save his country from “pro-North Korean” and “anti-state forces.”
But it ended almost as abruptly as it had started.
Thousands of citizens took to the streets, chanting “Impeach Yoon Suk Yeol!” Opposition lawmakers climbed the walls into the National Assembly as citizens pushed back police. Parliamentary aides used furniture and fire extinguishers to prevent armed paratroopers from entering the Assembly’s main hall. Inside, lawmakers who included members of Mr. Yoon’s own People Power Party, voted unanimously to strike down his martial law. Six hours after declaring it, Mr. Yoon appeared on television again, this time to retract his decision.
It was the shortest-lived and most bizarre martial law in the history of South Korea, which had had its share of military coups and periods of martial law before it became a vibrant democracy after the military dictatorship that ended in the late 1980s.
In the end, driven by his own impulsiveness and surrounded by a small group of insiders, who seldom said no to a leader known for angry outbursts, Mr. Yoon shot his own foot, according to a former aide and political analysts. Now his political future is on the chopping block, thrusting one of the United States’ most important allies in Asia into political upheaval and leaving many South Koreans in a state of shock.
On Wednesday, the opposition parties, which control the legislature, submitted an impeachment bill after Mr. Yoon did not respond to their demand that he resign because his martial law declaration had been unconstitutional. An editorial in the leading conservative daily Chosun Ilbo, which has often been friendly toward Mr. Yoon, now accused him of “insulting” South Korean democracy. South Koreans have not seen their leader declare martial law since former military dictator Chun Doo-hwan used it to seize power in 1979 and later massacre pro-democracy students.
“The best option Yoon has now is to resign,” said Sung Deuk Hahm, a professor of political science at Kyonggi University, west of Seoul. “As tragic as it may seem, what happened overnight showed the resilience and durability of South Korean democracy.”
Mr. Yoon did not immediately respond to the opposition’s demand. On Wednesday, all senior aides to Mr. Yoon tendered their resignations to Mr. Yoon, leaving him more isolated than ever. Analysts were skeptical about Mr. Yoon’s political future.
“I don’t think he can finish his five-year term,” said Kang Won-taek, a political scientist at Seoul National University.
On Wednesday, Mr. Yoon’s office said the president’s decision to declare martial law was an inevitable measure in accordance with the constitution to “restore and normalize the state of affairs” from political paralysis.
Mr. Yoon has grown increasingly despondent in recent months, particularly over escalating scandals surrounding him and his wife and the relentless political pressure from the opposition, said Mr. Hahm, who has known Mr. Yoon since before his election.
“Things have become too much for him,” Mr. Hahm said. “He became mentally unstable under political pressure.”
Mr. Yoon was surrounded by a handful of aides, including former military generals, who were not used to second-guessing their boss’s decision, said a former presidential aide to Mr. Yoon who agreed to discuss the president’s leadership style on the condition they not be identified. That small circle raised questions about how thoroughly Mr. Yoon prepared for martial law.
The former presidential aide said that as soon as he heard the declaration of martial law, he called contacts in Mr. Yoon’s office and other branches of the government. But none of them had advance knowledge of what was coming, he said.
Even top leaders of Mr. Yoon’s party said they learned of the declaration through the news media. Kim Byung-joo, an opposition lawmaker and former general, told MBC Radio on Wednesday that when he called army generals near the border with North Korea, none of them knew what was happening. Paratroopers mobilized to occupy the National Assembly showed none of the decisiveness and brutality their predecessors used in the 1980 crackdown on pro-democracy activists, when as many as hundreds were killed in the southern city of Gwangju during Mr. Chun’s period of martial law. On Wednesday, the soldiers peacefully retreated after the Assembly voted to repeal Mr. Yoon’s action.
Some opposition lawmakers and social media commentators speculated that Mr. Yoon might be preparing for martial law when he appointed Kim Yong-hyun, his chief bodyguard and former army general, as his defense minister in September. But members of his government called the idea a conspiracy theory, and not many people took it seriously.
Before he was catapulted into the presidential race in 2022, Mr. Yoon was a political neophyte. He was a star prosecutor who wielded the law to help imprison two former presidents, and was used to a strictly top-down culture.
He won the election by a razor-thin margin, thanks largely to the public’s discontent with his predecessor, Moon Jae-in. But, from the start, he laid out big ambitions, seemingly staking his claim for a legacy as a change maker in a gridlocked political system.
Mr. Yoon put South Korea back on a path toward embracing more nuclear power, mended ties with Japan and expanded military cooperation with the United States and Japan as he took a harder line against North Korea.
But little of his domestic agenda has worked out. His opponents won even greater control in the National Assembly in parliamentary elections this year. His government was accused of using prosecutors and criminal investigations to intimidate opposition leaders and crack down on news media he accused of spreading “fake news.” His approval rating plummeted to around 20 percent, as he repeatedly vetoed the opposition’s demands for independent investigations into allegations against his wife, Kim Keon Hee. The opposition also imposed large changes on his budget proposals for next year.
Mr. Yoon was often called a “tribal leader” by political analysts for his penchant for appointing loyal friends among former prosecutors and fellow high school alumni to key military and government posts.
One of them was Han Dong-hoon, Mr. Yoon’s loyal lieutenant when he was prosecutor general. As president, Mr. Yoon appointed Mr. Han as justice minister and later helped make him the head of his governing party. But they fell out over differences in how to handle allegations against the first lady.
They grew to dislike each other so much that Mr. Yoon considered Mr. Han a betrayer, according to former aides and local media.
“He must have felt that he was surrounded by enemies and that he must make a bold decision,” said Ahn Byong-jin, a political scientist at Kyung Hee University in Seoul. “But it’s mind-boggling that he didn’t know how it would be received by the National Assembly and the people.”
Mr. Hahm, the professor, said Mr. Yoon was an impulsive man surrounded by “sycophantic aides.” When he met the president after his party’s crushing defeat in parliamentary elections in April, he was surprised that Mr. Yoon had become more “obstinate and talkative,” Mr. Hahm said.
Mr. Yoon appeared to live with conflicting emotions, Mr. Hahm said. On one hand, he brimmed with optimism that things would work out almost miraculously, as they had in his previous career. On the other, he feared that he would end up a failed president with no positive legacy to speak of — a result he seemingly ensured when he moved to use the military against his opponents Tuesday night.
“I think those two emotions have combined to lead him to his decision,” he said.