Democratic Party of Korea Chair Lee Jae-myung speaks during his visit to Gadeok-do, Busan on Tuesday, moments before an unidentified man stabbed him in the neck. (Yonhap)

Tuesday's stabbing of Lee Jae-myung, the leader of the main opposition Democratic Party of Korea, showed that South Korea's politicians remain vulnerable to physical attacks despite several high-profile cases in the recent past.

Lee, 59, had been visiting the site of the new airport in Busan and was speaking to members of the media when an unidentified man approached him asking for an autograph before lunging to stab him in the neck, undetected and undeterred by anyone.

Lee is one of the most prominent figures in the opposition bloc, and is considered one of the main contenders for president in the next election. The liberal opposition leader ran against conservative current President Yoon Suk Yeol in the 2022 presidential election, which he lost by the closest margin in the country's history -- 0.73 percent.

Tuesday's incident is the latest in several assaults on political figures in the recent past.

In March 2022, then-Democratic Party leader Song Young-gil was attacked from behind while campaigning for then-presidential candidate Lee in Sinchon, Seoul, by a 69-year-old man wielding a hammer. The perpetrator was later identified to be a hard-line nationalist and extreme traditionalist YouTuber who supported Lee but was critical of Song.

In 2006, former President Park Geun-hye, then-leader of now-defunct Grand National Party, was attacked in the cheek with a box cutter while campaigning to support then-Seoul mayoral candidate Oh Se-hun in Sinchon, Seoul. The culprit, who had a previous record of eight criminal convictions and had assaulted another lawmaker of the same party in 2005, is thought to have acted on a personal grudge against the party.

Both cases sent shockwaves across the country but did not bring about any significant changes to existing laws.

Lawmakers conventionally rely on personal security teams and are not provided protection by the state, unless they make a personal request to the police, which has to be accepted on the discretion of the chief of the National Police Agency. The only exception is the chair of the National Assembly, whose protection is mandated by the Police Officials Act, along with the chief justices of the Supreme Court and Constitutional Court and the prime minister.

Ahead of Tuesday's stabbing of Lee, some 50 police officers had been dispatched and put on standby nearby, which is customary for events involving high-profile politicians. Police noted, however, that the officials had not been dispatched specifically for Lee's protection.

Lee and Park had both been given police protection during their respective runs for the presidency, as the law stipulates that the police must safeguard presidential candidates. Lee's former rival, Yoon, is given police protection according to the Presidential Security Act, as well as after retirement, as the law mandates protection for former heads of state.

Some security experts have called for legislative changes to safeguard politicians. In the journal article, "The Problems and Improvement Measures of Protection for Politician," published by the Korea Security Science Association, researchers Jo Sung-gu and Kim Tae-min write that attacks on politicians should be handled from the perspective of national security.

"As long as humanity persists, political activities will continue to do as well. The safety of a political leader is indisputably an important task, as he or she plays a crucial role in determining the future of the human race," the researchers write, urging a legislative process that would provide the legal grounds to protect politicians from physical attacks.