Four former and current executive officials of the Korean Confederation of Trade Unions are under investigation by the National Intelligence Service on suspicion of spying for North Korea.

The agency and the police searched the headquarters office of the nation’s major labor group last week. The search and seizure warrant issued by the court is said to have contained concrete grounds for suspicions that the service has secured for a long stretch of time.

They are suspected of contacting a North Korean espionage agent in Cambodia and Vietnam from 2017 to 2019 and following the agent's instructions to conduct anti-US and pro-North Korean activities in South Korea.

The truth will come out after the investigation and trial, but in view of the labor group’s erstwhile political struggle, it is hard to exclude the possibility of its connection with North Korea. Its calls for withdrawal of US troops and the US Terminal High Altitude Area Defense anti-missile system from South Korea are far from the protection of labor rights and interests.

Intelligence agents secured clues in 2017 and 2018, but failed to further investigations immediately. The same is true of probes into underground groups uncovered in Jeju and Changwon. The secret organizations recently reported by news media are suspected of carrying out orders from North Korea.

The intelligence agency under President Moon Jae-in is said to have brushed aside its agents’ requests for further investigation into North Korean espionage operations against South Korea. It may have prevented the investigations for fear that further probes would spoil the Moon government's efforts to make a show of inter-Korean relations.

When investigators of the agency asked for approval of further actions such as search and seizure, their managers are said to have delayed decisions, citing reasons such as the possibility of investigations throwing a wet blanket on inter-Korean relations. Sometimes they reportedly took days off to avoid authorizing further investigations. In the meantime, suspects contacted North Korean agents in Cambodia and Vietnam and carried out their instructions.

The Moon administration -- obsessed with relations with North Korea -- effectively relegated the intelligence agency into an organization for assisting dialogue with the North, not for catching spies and gathering intelligence. The number of cases in which the agency caught spy rings who worked for North Korea was 26 for a period from 2011 to 2016, then fell to three during Moon’s presidency. There’s very little chance that Pyongyang reduced its espionage operations sharply.

At present, the service gets involved in the investigation of spy suspects within the union group, but it will not be able to from January next year. Under the revised National Intelligence Service Act, which passed through the National Assembly in December 2020, its right to investigate North Korea’s espionage against South Korea will be transferred to the police. The then ruling majority Democratic Party of Korea rammed through the act despite public concerns and a strong opposition from the then opposition People Power Party. The NIS has been given a grace period of three years.

There is no reason to bury the investigation know-how the agency has accumulated for decades. Its investigative capability cannot be built in one year or two. The agency is concerned that once its right to investigate North Korean espionage is passed to the police, it will be almost impossible for foreign intelligence agencies to help. As in the latest cases of spies being detected, North Korea performs its anti-South espionage missions through overseas contact. Transfer of counterespionage to the police must be reconsidered.

But realistically it is difficult to revise the law immediately because the opposition party has an overwhelming majority. For the moment, the government needs to consider dispatching intelligence agents to the police or making the police recruit former agents.

Given North Korea’s escalating threat to South Korea, nonpartisan discussion is needed to strengthen the probe of the North’s espionage activities.