A Cheong Wa Dae decision made a decade ago has emerged as the top issue of the presidential election.

It was about whether the presidential office asked the North Korean authorities for their opinion on a UN resolution condemning the country’s human rights abuse of its residents. Former Foreign Minister Song Min-soon had made public a document that indicates Cheong Wa Dae asked Pyongyang for its position before it decided to abstain from the resolution.

Moon Jae-in, the presidential candidate of the Democratic Party of Korea who was then chief presidential secretary to President Roh Moo-hyun, has denied Song’s allegation. He said Cheong Wa Dae had notified the North of its decision to abstain.

Last October, Song revealed in his memoir that the Roh government had abstained from the resolution after asking the North for its opinion. Song said that Moon had taken the leading role in sounding out the North on the resolution.

When the memoir came out, Moon said he could not remember what he did at that time. He said in a TV debate last week, “Cheong Wa Dae judged North Korea’s reaction (to its decision) through the overseas network of the National Intelligence Service, not by asking the North directly.”

After the TV debate, Song disclosed what he says is a Cheong Wa Dae document contradicting Moon’s remark. According to Song, it contains the North Korean position, not the NIS’ assessment of the North’s reaction. Song said the NIS had contacted the North to prepare the document to deliver to Roh, who handed it to him.

The document says, “For the South to support the human rights resolution by anti-North countries is an outright violation of the Oct. 4 North-South Declaration, and cannot be justified for any reason. If the South decides to adopt the resolution, North-South relations will be jeopardized. … We will watch the South’s attitude carefully.”

He also made public a note he took of Roh’s utterance at a meeting held to decide on the resolution. It says, “I should not have asked. I did because Moon proposed to ask.”

In view of the wording of the document, it is hard to believe that it expressed the North’s reaction to the South’s notification.

Song has argued that Moon was lying. His rival candidates have criticized him, too. Moon countered that they were attempting to brand him as a follower of the North Korean regime. He also said he would sue Song.

The issue concerns the presidential front-runner’s honesty and views on North Korea.

The truth of the issue should be uncovered. Who wrote the document and how it was prepared should also be clarified. The minutes of the Cheong Wa Dae meeting and related NIS documents should be ascertained.

Moon is the most likely to win the election, which is just about two weeks away. North Korea issues have direct influence on the survival of the nation. He should have clear-cut views on North Korea and realistic strategies. Denials without showing tenable evidence cannot be accepted.

The argument that the issue was raised to defame him as a pro-North figure is unrelated to the essence of the issue. Moon should not try to evade Song’s allegations but provide tenable evidence.

If Song is right, the act of asking the North for its opinion would be a worrisome problem.

Jin Sung-joon, who leads the TV debate team of the Moon campaign, wrote about the issue on Facebook on Saturday, “Even if the government really asked the North Korean authorities for their position, what’s wrong with that?

As the post sparked controversy, he deleted it hours later.

Jin’s views on North Korea are problematic and risky. Asking the North for its opinion beforehand may put the national security of the South in trouble.

Considering his position as Moon’s campaign staff, his writing has raised suspicion that Moon may have similar views.

Moon should clarify what he thinks of Jin’s opinion.