North Korea demolished a liaison office shared with South Korea on Tuesday in response to President Moon Jae-in’s appeal to abide by previous agreements between the two sides and refrain from heightening tensions on the peninsula.

The office, which suspended operations in January due to concerns over the novel coronavirus, was set up in September 2018 in the northern border town of Kaesong to facilitate inter-Korean exchanges amid a reconciliatory mood fostered by a string of summits between Moon and North Korean leader Kim Jong-un.

The demolition of the liaison office was a slap in the face for Moon, who called on the North a day earlier to leave the door for dialogue open. He said his government would make “incessant” efforts to carry out his summit deals with Kim.

Moon also suggested that South and North Korea push for joint projects they could undertake on their own, instead of waiting for a breakthrough in stalled nuclear talks between the US and the North.

Tuesday’s action made a mockery of the Moon government’s efforts to placate Pyongyang’s anger over leaflets critical of the repressive regime flown by North Korean defectors across the border into the North.

Earlier in the day, the General Staff Department of the North’s Korean People’s Army said it would send troops “into the zones that had been demilitarized under the North-South agreement, turn the front line into a fortress and further heighten vigilance” against the South.

Pyongyang’s latest moves followed a statement issued Saturday by the North Korean leader’s increasingly powerful sister, Kim Yo-jong, which warned of the next step in making Seoul pay a dear price for failing to stop defectors from flying anti-North leaflets across the border.

Earlier last week, the North cut off all communication between the two Koreas, vowing to deal with the South as an “enemy.”

It is becoming apparent that the recalcitrant regime is using the leaflet issue as a pretext for its premeditated attempt to heighten tensions on the peninsula.

Pyongyang rebuffed the Moon administration’s recent moves to stop the sending of leaflets, including planned legislation to block it, as too late in coming.

The North appears to be increasing pressure on the South to reopen major lucrative cross-border projects at risk of violating US-led international sanctions imposed on the totalitarian state for its nuclear and ballistic missile tests.

Despite its eagerness to reconcile with Pyongyang, the Moon administration has hesitated to do so, as this would anger Washington, which has insisted on inter-Korean economic cooperation proceeding in step with significant progress in denuclearizing the North.

The remarks from Moon on Monday sparked speculation that he might be ready to pay more heed to the North’s call for the resumption of cross-border projects.

By extension, Pyongyang’s recent threats against Seoul seem designed to test the alliance between South Korea and the US and widen gaps between the allies. A prolonged deadlock in defense cost-sharing talks between Seoul and Washington, which might cause Trump to downsize the US forces stationed here, could have led North Korea to believe there was room to drive a wedge between them.

What should be noted is that Pyongyang’s attempt to intensify tensions on the peninsula might also be aimed at containing internal discontent over mounting economic difficulties caused by the prolonged international sanctions coupled with the outbreak of the novel coronavirus. Some North Korea experts forecast that the impoverished state will see its foreign currency reserves depleted in a couple of years if global sanctions remain in place.

This means that tightening sanctions against the North could result in getting it to take sincere steps toward denuclearization.

Hours after North Korea demolished the liaison office, South Korea’s presidential office, Cheong Wa Dae, warned of a strong response if North Korea further worsens the situation. The unusually strong warning from the Moon administration, issued after an emergency meeting of the National Security Council, should have come sooner.

Seoul needs to cope with Pyongyang’s return to a provocative mode based on clear and constant principles, so the Kim regime recognizes that any provocative acts down the road will incur a proportional response and severe consequences.

A North Korean official handling inter-Korean affairs said last week there would be “remorseful and painful times ahead” for South Korea.

The Moon government should maintain a firm stance to ensure it is the North that suffers more, unless it changes course.