The Constitutional Court’s ruling to disband the leftist Unified Progressive Party was a long-awaited, legitimate move to drive out dangerous radicals disguised as “liberals” from this society.

The court, announcing the result of its yearlong adjudication on a petition filed by the government, ruled Friday that the UPP should be disbanded because its objective and activities violate the basic democratic order protected by the Constitution.

Park Han-chul, president of the court, said that the UPP sought to establish “North Korean-style socialism” through violence, which posed “concrete” threats to South Korea, which is in an acute confrontation with North Korea.

Under the landmark decision endorsed by all but one of the nine justices, five lawmakers affiliated with the party ― including one already in jail ― also lost their parliamentary seats.

The ruling, which cannot be appealed, took effect immediately, which means the splinter party, founded in 2000 as the Democratic Labor Party and renamed in 2011, has gone down in history as the first Korean political party to be dissolved by the Constitutional Court.

The near-unanimous decision verified the government’s argument that the UPP’s constitution and platform followed North Korea’s constitution and the “juche” (self-reliance) ideology, and its aims including “revolutionary changes of society” threatened the country’s basic democratic order.

This does not come as a surprise as several key members of the UPP, including former Rep. Lee Seok-ki, are already serving jail terms after being convicted of instigating an armed rebellion to overthrow the government in the event of a war with North Korea.

An appeals court last August upheld Lee’s conviction on charges of sedition and violating the National Security Law, sentencing him to nine years in prison. The ruling proved that Lee and his followers in the UPP were a bunch of radicals seeking to overturn the democratic system in this society in line with the revolutionary tactics of socialists.

The Constitutional Court’s ruling ended a 13-month-long battle during which the court held 18 hearings and the Justice Ministry and the UPP submitted 170,000 pages of documents.

But the end of the legal war does not mean that we can lay down our arms against the staunch leftists. The UPP and its loyal supporters will not easily give in to what they call “a ploy to destroy conscientious liberal political forces.”

One more thing we should watch out for is the possibility that the same anachronistic radicals will attempt to regroup and create a surrogate party. Friday’s ruling includes a ban on any such attempt, but we are well aware that the radicals are good at reorganizing themselves.

Never again should they be allowed to attempt to gain a foothold in any sector of this society, not least the parliament.