A group of Navy SEALs emerged from the ink-black ocean on a winter night in early 2019 and crept to a rocky shore in North Korea. They were on a top-secret mission so complex and consequential that everything had to go exactly right.

The objective was to plant an electronic device that would let the US intercept the communications of North Korea’s reclusive leader, Kim Jong-un, amid high-level nuclear talks with President Donald Trump.

The mission had the potential to provide the US with a stream of valuable intelligence. But it meant putting American commandos on North Korean soil — a move that, if detected, not only could sink negotiations but also could lead to a hostage crisis or an escalating conflict with a nuclear-armed foe.

It was so risky that it required the President’s direct approval.

For the operation, the military chose SEAL Team 6’s Red Squadron — the same unit that killed Osama bin Laden. The SEALs rehearsed for months, aware that every move needed to be perfect. But when they reached what they thought was a deserted shore that night, wearing black wet suits and night-vision goggles, the mission swiftly unravelled.

A North Korean boat appeared out of the dark. Flashlights from the bow swept over the water. Fearing that they had been spotted, the SEALs opened fire. Within seconds, everyone on the North Korean boat was dead.

The SEALs retreated into the sea without planting the listening device.

Kim Jong Un travels to Beijing on his train on Monday. AP/PTI

The 2019 operation has never been publicly acknowledged, or even hinted at, by the US or North Korea. The details remain classified and are being reported here for the first time. The Trump administration did not notify key members of Congress who oversee intelligence operations, before or after the mission. The lack of notification may have violated the law.

The White House declined to comment.

This account is based on interviews with two dozen people, including civilian government officials, members of the first Trump administration and current and former military personnel with knowledge of the mission. All of them spoke on the condition of anonymity because of the mission’s classified status.

Several of those people said they were discussing details about the mission because they were concerned that Special Operations failures are often hidden by government secrecy. If the public and policymakers become aware only of high-profile successes, such as the raid that killed bin Laden in Pakistan, they may underestimate the extreme risks that American forces undertake.

The military operation on North Korean soil, close to American military bases in South Korea and the Pacific region, also risked setting off a broader conflict with a hostile, nuclear-armed and highly militarised adversary.

The New York Times proceeds cautiously when reporting on classified military operations. The Times has withheld some sensitive information on the North Korea mission that could affect future Special Operations and intelligence-gathering missions.

It is unclear how much North Korea was able to discover about the mission. But the SEAL operation is one chapter in a decades-long effort by US administrations to engage North Korea and constrain its nuclear weapons programmes. Almost nothing the US has tried — neither promises of closer relations nor the pressure of sanctions — has worked.

In 2019, Trump was making a personalised overture to Kim, in search of a breakthrough that had eluded prior Presidents. But those talks collapsed, and North Korea’s nuclear programme accelerated. The US government estimates that North Korea now has roughly 50 nuclear weapons and missiles that can reach the West Coast. Kim has pledged to keep expanding his nuclear programme “exponentially” to deter what he calls US provocations.

Blind spots

The SEAL mission was intended to fix a strategic blind spot. For years, US intelligence agencies had found it nearly impossible to recruit human sources and tap communications in North Korea’s insular authoritarian state.

Gaining insight into Kim’s thinking became a high priority when Trump first took office. The North Korean leader seemed increasingly unpredictable and dangerous, and his relationship with Trump had lurched erratically between letters of friendship and public threats of nuclear war.

In 2018, relations seemed to be moving towards peace. North Korea suspended nuclear and missile tests, and the two countries opened negotiations, but the US still had little insight into Kim’s intentions.

Amid the uncertainty, US intelligence agencies revealed to the White House that they had a fix for the intelligence problem: a newly developed electronic device that could intercept Kim’s communications.

The catch was that someone had to sneak in and plant it.

Even for Team 6, the mission would be extraordinarily difficult. SEALs who were more used to quick raids in places like Afghanistan and Iraq would have to survive for hours in frigid seas, slip past security forces on land, perform a precise technical installation and then get out undetected.

Getting out undetected was vital. In Trump’s first term, top leaders in the Pentagon believed that even a small military action against North Korea could provoke catastrophic retaliation from an adversary with roughly 8,000 artillery pieces and rocket launchers aimed at the approximately 28,000 American troops in South Korea, and nuclear-capable missiles that could reach the US.

But the SEALs believed they could pull off the mission because they had done something like it before.

In 2005, SEALs used a mini-sub to go ashore in North Korea and leave unnoticed, according to people familiar with the mission. The 2005 operation, carried out during the presidency of George W. Bush, has never before been reported publicly.

The SEALs were proposing to do it again. In the autumn of 2018, while high-level talks with North Korea were underway, Joint Special Operations Command, which oversees Team 6, received approval from Trump to start preparing, military officials said. It is unclear whether Trump’s intent was to gain an immediate advantage during negotiations or if the focus was broader.

Joint Special Operations Command declined to comment.

The plan called for the navy to sneak a nuclear-powered submarine, nearly two football fields long, into the waters off North Korea and then deploy a small team of SEALs in two mini-subs, each about the size of a killer whale, that would motor silently to the shore.

The mini-subs were wet subs, which meant the SEALs would ride immersed in 40 degree ocean water for about two hours to reach the shore, using scuba gear and heated suits to survive.

Near the beach, the mini-subs would release a group of about eight SEALs who would swim to the target, install the device and then slip back into the sea.

But the team faced a serious limitation: It would be going in almost blind.

Typically, Special Operations forces have drones overhead during a mission, streaming high-definition video of the target, which SEALs on the ground and senior leaders in far-off command centres can use to direct the strike in real time. Often, they can even listen in on enemy communications.

But in North Korea, any drone would be spotted. The mission would have to rely on satellites in orbit and high-altitude spy planes in international airspace kilometres away that could provide only relatively low-definition still images, officials said.

Those images would arrive not in real time, but after a delay of several minutes at best. Even then, they could not be relayed to the mini-subs because a single encrypted transmission might give the mission away. Everything had to be done under a near blackout of communications.

If anything awaited the SEALs on shore, they might not know until it was too late.

Operation unravels

SEAL Team 6 practised for months in US waters and continued preparations into the first weeks of 2019. That February, Trump announced that he would meet Kim for a nuclear summit in Vietnam at the end of the month.

For the mission, SEAL Team 6 partnered with the navy’s premier underwater team, SEAL Delivery Vehicle Team 1, which had been doing mini-sub espionage for years. The SEALs boarded the nuclear-powered submarine and headed for North Korea. When the submarine was in the open ocean, and about to enter a communications blackout, Trump gave the final go-ahead.

It is unclear what factors Trump weighed when approving the SEAL mission. Two of his top national security officials at that time — his national security adviser, John Bolton, and the acting defence secretary, Patrick M. Shanahan — declined to comment for this article.

The submarine neared the North Korean coast and launched two mini-subs, which motored to a spot about 90 metres from shore, in clear shallow water.

Mission planners had tried to compensate for having no live overhead video by spending months watching how people came and went in the area. They studied fishing patterns and chose a time when boat traffic would be scant. The intelligence suggested that if SEALs arrived silently in the right location in the dead of night in winter, they would be unlikely to encounter anyone.

The night was still and the sea was calm. As the mini-subs glided toward the target, their sensors suggested that the intelligence was correct. The shore appeared to be empty.

The mini-subs reached the spot where they were supposed to park on the sea floor. There, the team made what may have been the first of three small mistakes that seemed inconsequential at the time but may have doomed the mission.

In the darkness, the first mini-sub settled on the sea floor as planned, but the second overshot the mark and had to do a U-turn, officials said.

The plan called for the mini-subs to park facing the same way, but after the second sub doubled back, they were pointing in opposite directions. Time was limited, so the group decided to release the shore team and correct the parking issue later.

Sliding doors on the subs opened, and the SEALs — all gripping untraceable weapons loaded with untraceable ammunition — swam silently underwater to shore with the listening device.

Every few metres, the SEALs peeked above the black water to scan their surroundings. Everything seemed clear.

That might have been a second mistake. Bobbing in the darkness was a small boat. On board was a crew of North Koreans who were easy to miss because the sensors in the SEALs’ night-vision goggles were designed in part to detect heat, and the wet suits the Koreans wore were chilled by the cold seawater.

The SEALs reached shore thinking they were alone, and started to remove their diving gear. The target was only a few hundred metres away.

Back at the mini-subs, the pilots repositioned the sub that was facing the wrong way. With the sliding cockpit doors open for visibility and communication, a pilot revved the electric motor and brought the sub around.

That was probably a third mistake. Some SEALs speculated afterwards in briefings that the motor’s wake might have caught the attention of the North Korean boat. And if the boat crew heard a splash and turned to look, they might have seen light from the subs’ open cockpits glowing in the dark water.

The boat started moving towards the mini-subs. The North Koreans were shining flashlights and talking as if they had noticed something.

Some of the mini-sub pilots told officials in debriefings afterwards that from their vantage point, looking up through the clear water, the boat still seemed to be a safe distance away and they had doubted that the mini-subs had been spotted. But the SEALs at the shore saw it differently. In the dark, featureless sea, the boat to them seemed to be practically on top of the mini-subs.

With communications blacked out, there was no way for the shore team to confer with the mini-subs. Lights from the boat swept over the water. The SEALs didn’t know if they were seeing a security patrol on the hunt for them or a simple fishing crew oblivious to the high-stakes mission unfolding around them.

A man from the North Korean boat splashed into the sea.

If the shore team got into trouble, the nuclear-powered sub had a group of SEAL reinforcements standing by with inflatable speedboats. Farther offshore, stealth rotary aircraft were positioned on US Navy ships with even more Special Operations troops, ready to sweep in if needed.

The SEALs faced a critical decision, but there was no way to discuss the next move. The mission commander was far away on the big submarine. With no drones and a communications blackout, many of the technological advantages that the SEALs normally relied on had been stripped away, leaving a handful of men in wet neoprene, unsure of what to do.

As the shore team watched the North Korean in the water, the senior enlisted SEAL at the shore chose a course of action. He wordlessly centred his rifle and fired. The other SEALs instinctively did the same.

Compromise & escape

If the SEALs were unsure whether the mission had been compromised before they fired, they had no doubt afterwards. The plan required the SEALs to abort immediately if they encountered anyone. North Korean security forces could be coming. There was no time to plant the device.

The shore team swam to the boat to make sure that all of the North Koreans were dead. They found no guns or uniforms. Evidence suggested that the crew, which people briefed on the mission said numbered two or three people, had been civilians diving for shellfish. All were dead, including the man in the water.

Officials familiar with the mission said the SEALs pulled the bodies into the water to hide them from the North Korean authorities. One added that the SEALs punctured the boat crew’s lungs with knives to make sure their bodies would sink.

The SEALs swam back to the mini-subs and sent a distress signal. Believing the SEALs were in imminent danger of capture, the big nuclear submarine manoeuvred into shallow water close to the shore, taking a significant risk to pick them up. It then sped toward the open ocean.

All the US military personnel escaped unharmed.

Immediately afterwards, US spy satellites detected a surge of North Korean military activity in the area, US officials said. North Korea did not make any public
statements about the deaths, and US officials said it was unclear whether the North Koreans ever pieced together what had happened and who was responsible.

The nuclear summit in Vietnam went ahead as planned at the end of February 2019, but the talks quickly ended with no deal.

By May, North Korea had resumed missile tests.

Trump and Kim met once more that June in the Demilitarised Zone between North and South Korea. It made for dramatic television, with Trump even stepping across into North Korea. But the brief meeting yielded little more than a handshake.

In the months that followed, North Korea fired more missiles than in any previous year, including some capable of reaching the US. Since then, the US estimates, North Korea has amassed 50 nuclear warheads and material to produce about 40 more.

The aborted SEAL mission prompted a series of military reviews during Trump’s first term. They found that the killing of civilians was justified under the rules of engagement, and that the mission was undone by a collision of unfortunate occurrences that could not have been foreseen or avoided. The findings were classified.

When President Joseph R. Biden succeeded Trump, the gravity of the North Korea mission attracted renewed scrutiny. Biden’s defence secretary, Lloyd J. Austin III, ordered an independent investigation, conducted by the lieutenant general in charge of the army inspector-general’s office.

In 2021, the Biden administration briefed key members of Congress on the findings, a former government official said.

Those findings remain classified.

New York Times News Service