SEOUL, South Korea – North Korea has put its border artillery units on standby after angrily claiming that South Korea has conducted drone operations in the night skies over its capital, Pyongyang.

On Friday, the regime of North Korean leader Kim Jong-un went public with complaints that drones had dropped leaflets on the city three times this month. Photos released by state media appeared to show a flying wing-style drone and stacks of apparent propaganda leaflets.

Over the weekend, one of North Korea’s most senior figures warned the South faced “a horrible disaster” if it did not desist, and on Monday North Korea announced that it had ordered eight border artillery brigades to be placed on heightened alert.

There were also signs that Pyongyang was preparing explosives to demolish road and rail links crossing the Demilitarized Zone (DMZ,) a move it announced last week. That is purely symbolic — the border crossings are entirely closed — but analysts say it constitutes just another sign that the Kim regime has dropped all pretense of diplomacy and is further fortifying itself against its southern neighbor.

“We will take a strong corresponding retaliatory action … in case drones carrying anti-[North Korea] political motivation rubbish from [South Korea] across the border infiltrate into the territorial sky of [North Korea],” Kim Yo-jong, Mr. Kim’s influential sister, told North Korea’s state-controlled press.

North Korea’s harsh complaints have raised speculation here over whether Seoul has initiated a deniable information operation against its hostile neighbor. In August, South Korean President Yoon Suk Yeol announced a new strategy of granting North Korean citizens, trapped for decades behind steep walls of censorship, access to outside information.

Some say the reported recent drone incursions could be the first probe. Seoul’s opaque statements on the matter have infuriated the North and raised eyebrows in the South.

Deniability

One defense analyst said on background that if South Korean drones crossed the border, they likely had official sanction. Drones capable of reaching Pyongyang from the DMZ would not be legal for civilians, he said.

Drones fall under the international Missile Technology Control Regime, to which South Korea is a signatory.

“The MTCR means that countries that manufacture and maintain these technologies have strict controls over how they can be used,” said the source, who is familiar with the global defense industry. “Could a civilian store sell drones that can fly 160 [kilometers]? I doubt it: In most countries, you need a by-your-leave from authorities.”

Pyongyang is 160 kilometers, or about 99 miles, from the heavily armed demilitarized band that separates the two Koreas on the peninsula.

But Yang Uk, a security expert at Seoul’s Asan Institute, said it was not certain the Yoon government played a role in the drone flights.

“North Korea has been infiltrating drones – civilian drones from Chinese companies – since 2014,” he said. “These technologies are all over the civilian and commercial sectors.”

Another possibility, suggested the conservative Chosun Ilbo newspaper, was that the drones could have launched from a vessel in the Yellow Sea, a shorter route that would evade border air defenses.

Pyongyang lies 26 miles inland. Any vessel would need to operate well offshore to evade North Korean naval patrols.

Mr. Kim’s indignation may be because South Korea is playing games North Korea long ago mastered: drone intrusions and operations expressly designed to give the government deniability over its role.

Defense Minister Kim Yong-hyun first denied the South’s military had deployed drones over the DMZ. Subsequently, the Joint Chiefs said they could neither confirm or deny the North’s claims.

In Pyongyang, however, Ms. Kim was scathing.

“Such an attitude of neither denying or admitting the case proves that the military admitted by itself that it is the chief criminal or accomplice of the current incident,” she said.

A press statement from Seoul’s Defense Ministry said Pyongyang was using a “typical trick” to promote “South-South conflict” — a reference to ideological divisions.

The liberal Seoul newspaper The Hankyoreh editorialized that the incident “could lead to further controversy [in North Korea], as it could even lead to speculations that the military failed to detect or assisted the deployment of drones by a South Korean civilian group, so the government needs to explain itself.”

South Korea’s Unification Ministry accused Pyongyang of hyping the incident to shore up its position at home.

“North Korea has repeatedly fabricated and exaggerated external crises to consolidate its vulnerable regime and control its people,” the ministry spokesman stated. “This sudden drone incident appears to have a similar purpose.”

Pyongyang may be concerned that Seoul is targeting a regime soft spot: information control.

Officials who have briefed Seoul correspondents on Mr. Yoon’s information-dispersal strategy have declined to say what tactics might be used. The Hankyoreh, citing an unnamed defense official, reported that Seoul was being “deliberately ambiguous.”

Moon Chung-in, an academic, who advised the previous Seoul administrations that engaged Pyongyang, speculated that Seoul’s “psychological warfare units” were responsible.

Defense experts said the situation remained murky.

Mr. Yang said the alleged leaflets shown in North Korean media looked unsophisticated, and their container was not ideal for airborne dispersion.

“This is totally new,” he said. “I cannot see the MO of the military, intelligence or the balloon guys, so if it is a deniable operation, it is quite a success.”

Lines between private and official anti-Pyongyang activities have blurred in recent times, said Chris Green, a Korea specialist with International Crisis Group.

“The armed forces-vs.-activists dichotomy is not at all black and white in South Korea,” he said. “These activities are all characterized by an interplay of state and civil actors.”

Civic activities that infuriate the North — cross-DMZ balloon flights, the erection of Christmas trees close to the frontier, northward radio broadcasts — require official sign-off, he said.

But if Seoul was behind the drone flights, they carry a “high risk-reward profile” Mr. Green said, as they are “directly targeted at regime security.”

Korean cloud confrontations

Multiple indications are that neither the North or South Korean air defenses can halt drone or even balloon intrusions. While drones are proving deadly and destructive in Ukraine and the Middle East, the peninsula’s aerial competition is at a lower intensity.

In 2022, three North Korean drones crossed the DMZ and loitered over sensitive Seoul sites, including the presidential and defense ministry compound and two international airports. Efforts to down them failed, embarrassing the South’s military.

South Korean rights activists in turn have, for decades, been floating balloons carrying anti-regime messaging and media across the DMZ.

This year, the North began a novel retaliation campaign: unleashing balloons loaded with trash southward. They have caused no deaths, but have caused physical damage and delays at airports.

Seoul boasts dense air defenses — including camouflaged Patriot missiles on hillsides and chain guns on high-rise roofs — but is unable to fire during peacetime: Falling debris would likely cause casualties in one of the world’s most densely populated spaces.

The greater Seoul area, 30 miles south of the DMZ, houses half of South Korea’s 51 million people.

Despite Monday’s rumbles, there was no alarm in Seoul. Some residents say even if their government accelerates tensions, other feet are ready to hit the brakes.

“The news says tensions are rising, but markets are up and foreigners are net buyers,” said Ahn Hae-kyun, a Seoul-based trader. “We all know that a decision for war is down to the Americans.”

• Andrew Salmon can be reached at asalmon@washingtontimes.com.