The counterespionage authorities are said to be investigating an officer of a progressive party and two others on Jeju Island in relation to suspicions they have been spying for North Korea.

It is the Yoon Suk Yeol administration's first known investigation of a spy ring acting for Pyongyang.

The authorities are also said to have captured indications of similar underground organizations in three other cities -- Changwon and Jinju in South Gyeongsang Province and Jeonju in North Jeolla Province. They assume there are more underground groups.

The National Intelligence Service and the police have tracked the Jeju spy ring for more than five years. The authorities raided the party and a farmers group in Jeju on two occasions late last year.

According to the search warrants that media revealed, the party officer met secretly a North Korean agent at Angkor Wat, Cambodia, in July 2017, received education in a Cambodian hideout for three days about how to form an underground group and transmit and decipher coded messages. Back in Jeju, the party officer won over two persons -- a senior member of a labor group and a farmer-activist -- and formed an underground group.

The warrants say they received instructions from North Korea until November last year to condemn President Yoon, struggle against conservative politicians, demand the suspension of US-Korea combined military exercises, and oppose the introduction of advanced US weapons to South Korea. They reported to Pyongyang that they had actually carried out some of the instructions.

This case is similar in method of operation to that of the North Chungcheong Comrade Party for Independent Unification uncovered in August 2021. At that time, the authorities arrested three "comrades." They contacted North Korean agents abroad, formed an underground organization in Cheongju, North Chungcheong, and instigated anti-US protests. They received directives from and made reports to North Korea in encrypted files.

What has been exposed so far may be the tip of an iceberg. The Moon Jae-in administration obsessed with making a show of peace with North Korea effectively sat on its hands in hunting down people spying for the North.

According to data compiled by the Korea Institute of Liberal Democracy, a total of 26 espionage cases were uncovered for six years from 2011 to 2017 -- about four cases a year on average, but the number dropped to three for three years from 2017 to 2020, a period when Moon was the president. Even the investigations of the three cases are said to have begun in the days of Moon's predecessor, President Park Geun-hye.

A former North Korean senior colonel who spent 30 years working his way to the top ranks of the North's spy agencies before defecting to South Korea claimed in an interview with the BBC in 2021 that North Korean operatives were playing an active role in various civil society organizations as well as important institutions in South Korea. He said that a North Korean agent was dispatched and worked at the presidential office in South Korea for five to six years and returned to North Korea in the early 1990s.

The late Hwang Jang-yop, a key architect of North Korea's juche (self-reliance) ideology who defected to South Korea in 1997, once estimated about 50,000 resident agents were secretly acting for Pyongyang in South Korea.

It would be reasonable to suspect that North Korea's spy agencies are not sitting back but maneuvering actively behind the scenes.

Under the pretext of reforming the National Intelligence Service, the Moon administration drafted a bill to transfer the service's right to chase and investigate spies acting for North Korea to the police, and the bill passed the National Assembly in December 2020.

It takes specialized investigation know-how to uncover spies and gather evidence. Counterespionage investigations often require the help of overseas intelligence networks. It differs from criminal investigations by the police. There are concerns that the government's ability to hunt down spies will weaken if the anti-communism investigation authority is handed over to the police from Jan. 1 next year. It is difficult to expect an adequate level of investigation from the inexperienced police. This must be rectified immediately.