How polarised politics led South Korea to a plunge into martial law

Just over two years later, Yoon Suk Yeol's brief declaration of martial law Tuesday shocked South Koreans who had hoped that tumultuous era of military intervention was behind them.

Yoon Suk Yeol won South Korea's highest office in 2022 by a threadbare margin, the closest since his country abandoned military rule in the 1980s and began holding free presidential elections.

Just over two years later, Yoon's brief declaration of martial law Tuesday shocked South Koreans who had hoped that tumultuous era of military intervention was behind them. Thousands of protesters gathered in Seoul to call for his arrest. Their country, regarded as a model of cultural soft power and an Asian democratic stalwart, had suddenly taken a sharp turn in another direction.

But the events that led to Yoon's stunning declaration Tuesday -- and his decision six hours later to lift the decree after parliament voted to block it -- were set in motion well before his razor-thin victory. They were a dramatic illustration of South Korea's bitterly polarized politics and the deep societal discontent beneath the surface of its rising global might.

It all came to a head when Yoon, once a hard-charging prosecutor who investigated former presidents, found himself on the receiving end of a political onslaught by a galvanized opposition.

Victory, but no mandate

Yoon, a conservative leader, has never been popular in South Korea. He won election by a margin of only 0.8 percentage point. The vote, analysts said, was more a referendum on his liberal predecessor's failures than an endorsement of Yoon. The bitterness of the campaign was reflected in a statement by Yoon's main opponent, Lee Jae-myung, who would go on to lead the opposition to the Yoon government in parliament.

"I sincerely ask the president-elect to lead the country over the divide and conflict and open an era of unity and harmony," he said.

Yoon, 63, was an unlikely figure to guide the nation to reconciliation. As prosecutor general, he helped convict and imprison a former leader of his own party, Park Geun-hye​, after her impeachment as president. Specializing in corruption cases, he had also pursued another former president and the head of Samsung.

As Yoon investigated Park, the administration he worked for continued a long pattern in South Korea in which new leaders launch inquiries into their predecessors, contributing to the rancorous nature of the country's politics.

Running for office, Yoon vehemently criticized his former boss, President Moon Jae-in, a progressive, for meeting with North Korea's leader, Kim Jung Un, but failing to stop his nuclear ambitions. He called for ratcheting up military drills and for strict enforcement of sanctions on the North, envisioning a South Korea that wielded its influence as a major US ally in Asia.

"Peace is meaningless unless it is backed by power," Yoon said during the campaign. "War can be avoided only when we acquire an ability to launch preemptive strikes and show our willingness to use them."

The approach won him favor in Washington, where the Biden administration was glad to have South Korea align itself more closely with U.S. positions as a bulwark against China. But it did little for him at home, where he was locked in perpetual war with the opposition even as his domestic challenges mounted.

A cauldron of discontent

Despite South Korea's growing influence worldwide -- in business, film, television and music -- vertiginous inequality has fueled widespread discontent at home. Skyrocketing home prices have forced people to live in ever-smaller spaces at ever-greater cost. Recent college graduates have struggled to find suitable work, sometimes accusing older generations of locking them out.

Many young people, facing uncertain economic prospects, are reluctant to marry or have children, and the country has both a rapidly aging population and the world's lowest birthrate. Increasingly, voters have blamed their political opponents, as well as immigrants and feminists.

Critics of Yoon, whose campaign promised to abolish South Korea's ministry of gender equality, accused him of playing on some of those divides, saying he stoked biases, especially among young men.

From the start, however, Yoon faced two obstacles.

The opposition Democratic Party held on to its majority in the National Assembly and then expanded it in parliamentary elections in April, making him the first South Korean leader in decades to never have a majority in parliament. And then there were his own dismal approval ratings.

Yoon's toxic relationship with opposition lawmakers -- and their vehement efforts to oppose him at every turn -- paralyzed his pro-business agenda for two years, hindering his efforts to cut corporate taxes, overhaul the national pension system and address housing prices.

An election fueled by vitriol

Yoon's party had seen the 2024 elections as an opportunity to win back the chamber.

Instead the crises and scandals built. A Halloween celebration became a deadly catastrophe, and North Korea ramped up its threats. Doctors went on strike, describing a medical system of harsh working conditions and low wages. Allegations of corruption involving Yoon's wife and a $2,200 Dior pouch roiled his party, with one senior member comparing her to Marie Antoinette.

Protests organized on social media by rival political activists became common, with a rough division of churchgoers and other older citizens on the right, and mostly younger people on the left.

The election devolved into vicious recriminations, with left-wing protesters calling Yoon a "national traitor" over what they called his anti-feminist policies and attacks on news outlets he accused of spreading "fake news." They also criticized him for the Halloween crowd crush and his efforts to improve ties with Japan, the onetime colonial ruler of Korea.

Opposition leaders warned that Yoon was taking South Korea onto the path of "dictatorship." In turn, members of Yoon's party called the opposition "criminals," and voters on the right rallied against what they called "pro-North Korean communists."

(Yoon echoed that language Tuesday in his declaration of martial law, saying he was issuing it "to protect a free South Korea from the North Korean communist forces, eliminate shameless pro-North Korean and anti-state forces.")

The election in April ultimately granted the opposition one of the biggest parliamentary majorities in South Korea in decades.

Many South Koreans called it "Judgment Day." But the outcome also solidified the deadlock in government, restricting either party's ability to agree on the national budget or address the public's complaints. The acrimony only deepened as the opposition moved to impeach several members of Yoon's government.

After the April vote, the prime minister and many of the president's top aides resigned. Yoon's chief of staff relayed a message from the president, who was quoted as saying he would "overhaul the way the government is run."

But by Tuesday night, Yoon had turned startlingly defiant. He declared that "the National Assembly, which should have been the foundation of free democracy, has become a monster that destroys it."

Not long after, as protesters rushed to the gates of the National Assembly, lawmakers voted to lift the president's measure. Lee, the opposition leader, who survived a stabbing attack in January and later staged a hunger strike against the Yoon government, said Yoon had "betrayed the people."

Hours later, Yoon said he would comply with the legislature's order. But even then, with his political future now thrown into profound uncertainty, he added a plea.

"I call on the National Assembly," he said, "to immediately stop the outrageous behavior that is paralyzing the functioning of the country with impeachments, legislative manipulation and budget manipulation."