In his last known letter to a US president, an emotional Kim Jong Un rebuked Donald Trump for carrying out scheduled joint military exercises with South Korea.
“I am clearly offended, and I do not want to hide this feeling from you,” Kim wrote in August 2019. “If you do not think of our relationship as a stepping stone that only benefits you, then you would not make me look like an idiot that will only give without getting anything in return.”
The letter marked the end of a turbulent period in US-North Korean relations that included Trump’s threat to inflict “fire and fury like the world has never seen” upon the east Asian dictatorship and culminated in a series of historic meetings between the two men.
Having failed to secure the sanctions relief and security guarantees he was seeking, however, Kim has eschewed diplomacy ever since — focusing instead on upgrading his nuclear weapons programme.
Now, in spite of tough international sanctions and extreme self-imposed isolation during the coronavirus pandemic, experts warn that North Korea has made such rapid progress with its military goals that existing arrangements for the defence of South Korea, Japan and the US could soon be rendered obsolete.
“North Korea is on its way to perfecting its nuclear programme,” says Sue Mi Terry, a former CIA analyst who heads the Asia programme at the Wilson Center think-tank in Washington. “I think there is a serious risk that a North Korean crisis could erupt while we are all focused on China potentially invading Taiwan.”
Kim is showing no signs of slowing down. In his New Year’s address, he declared he would “exponentially increase” nuclear weapons production in 2023 and stressed his willingness to use his nuclear arsenal for offensive as well as defensive purposes.
Pyongyang’s advances in weapons development, and its adoption of a more aggressive nuclear doctrine, have prompted Seoul and Tokyo to seek greater reassurance from its US allies, who responded with increased patrols of nuclear-capable military assets on and around the Korean peninsula. The Biden administration has also vowed to “end” the Kim regime if it ever used nuclear weapons.
But some analysts worry that a strategy to meet strength with strength risks making conflict even more likely.
“Every time the Americans do something to reassure the South Koreans that they are prepared to defend them, they weaken their assurances to the North Koreans that they are not preparing to attack them,” says Sheen Seong-ho, a professor of international security at Seoul National University. “The North Koreans are sending the message that they are not prepared to go down without a fight.”
Preparing for battle
Cigarette in hand, a beaming Kim last month oversaw North Korea’s first known test of a large-diameter solid rocket motor at a test site in the country’s western North Pyongan province.
The test brought his regime a step closer to acquiring a solid-propellant intercontinental ballistic missile that, unlike liquid fuel missiles, can be fuelled in secret before they are deployed, giving adversaries far less time to conduct a preventive strike.
It is one of many recent examples of Pyongyang approaching or crossing key technical thresholds that are making its nuclear arsenal increasingly versatile and difficult to destroy or defend against.
North Korea has tested the Hwasong-17 intercontinental ballistic missile which has an estimated range of 15,000km — within striking distance of the US mainland. It has also tested a rocket fitted with a conical “manoeuvring re-entry vehicle”, or MaRV, which is potentially harder to intercept and destroy than a standard ballistic warhead.
But the development that most worries policymakers in Seoul, Tokyo and Washington is North Korea’s new generation of lower yield tactical and battlefield nuclear weapons.
On New Year’s Day, North Korea test-fired its “super-large multiple launch rocket system”, which Kim has claimed can strike anywhere in South Korea.
These lower-yield weapons “can be used more precisely to target specific enemy assets such as ports, airfields, ships, or concentrations of troops,” says Ankit Panda, a nuclear weapons expert at the Carnegie Endowment think-tank in Washington.
Not only is their threshold for use much lower than for ICBMs, he adds, the decision to use them is more likely to be delegated to field commanders, “increasing the risk of an accident, miscommunication or miscalculation resulting in nuclear use”.
In a 20-day period between late September and early October, North Korea launched 15 newly developed missiles capable of delivering tactical nuclear warheads as part of a simulated nuclear attack on South Korean and US assets.
The launches, attended by Kim himself, included short-range ballistic missiles fired from mobile road and rail platforms and another fired over Japan from a site near the border with China.
“North Korea fired more than twice as many missiles last year as were launched during the entirety of the reigns of former leaders Kim Il Sung and Kim Jong Il put together,” says Jeongmin Kim, an analyst with Seoul-based information service NK Pro.
“It is no longer strictly accurate to describe these launches simply as ‘tests’,” she adds. “Rather, North Korea is demonstrating to its adversaries that its nuclear forces are operational and ready to use.”
In September, Kim adopted a more aggressive nuclear policy that outlines an unusually low threshold for use, such as pre-emptive strikes in a range of vaguely-defined scenarios.
The law stipulates that in the event of an attack on the “state leadership and command organisation”, a North Korean nuclear strike would be launched “automatically and immediately” — suggesting Kim has already envisioned scenarios where command and control could be delegated over parts of his arsenal.
The policy enshrines comments made by Kim in April and reiterated at this month’s party congress that beyond the “primary mission” of preventing war, his nuclear weapons had a “secondary mission” if his country’s “fundamental interests” were threatened.
This has exacerbated fears that North Korea increasingly sees its nuclear arsenal as a means to engage in nuclear blackmail against the South — or even to start and win a conflict.
“This is not the first time North Korea established a nuclear policy law, but in the past they said it was for deterrence purposes,” says Kim Gunn, South Korea’s special representative for Korean peninsula peace and security affairs. “But [now] they say it is not only for deterrence, but [also] for a pre-emptive strike, and the conditions are very much arbitrary, which means they can use their tactical nuclear weapons at the time of their choosing.”
Some critics believe the Biden administration has not paid enough attention to North Korea, particularly as it remains preoccupied with Ukraine and increases its focus on China.
A senior US official said the administration has made multiple efforts to engage with North Korea, and that it has been clear that Washington was willing to negotiate without preconditions. But he said the response from Pyongyang since the Biden administration came to office could be summed up as “pretty much radio silence”.
That has left the US with few options other than to focus on reassuring their allies.
In recent months the US has deployed fighter jets and B52 bombers capable of carrying nuclear weapons to the Korean peninsula as part of a commitment made by US defence secretary Lloyd Austin in November last year to send nuclear-capable assets to the region on a “constant” and “routine” basis.
These shows of force are designed to reassure policymakers in Seoul of Washington’s “ironclad commitment” to South Korean security.
But Seukhoon Paul Choi, a former strategist at the US-South Korea joint warfighting headquarters, says the US is prioritising symbolic gestures over substantive changes to the way the alliance operates.
“The US still seems to see the problem as primarily an issue of ally psychology, rather than as a transformed security challenge,” says Choi, now a nuclear security fellow at the Rand Corporation think-tank in Washington.
He notes that South Korean policymakers remain unsure of Washington’s thinking surrounding the circumstances in which the US might use nuclear weapons on the Korean peninsula, feeding anxiety in Seoul as to whether the US would really risk North Korean nuclear retaliation against one of its own cities by coming to South Korea’s defence.
That concern is shared by many in the Japanese national security establishment. Sugio Takahashi, head of defence policy division at the National Institute for Defense Studies in Tokyo, says that the US, South Korea and Japan need to conduct exercises that simulate a scenario in which nuclear weapons are used.
“The reality is very little such preparations are actually taking place and there is awareness both in Japan and South Korea that they need to make progress on this front,” says Takahashi.
Panda, of the Carnegie Endowment, says there will always be a limit to the reassurance that US policymakers can offer their east Asian counterparts regarding America’s willingness to use its nuclear weapons as the ultimate decision resides solely with the president.
A senior US official disputes the notion that Washington is not communicating sufficiently with its allies on nuclear use, calling the level of co-ordination “truly extraordinary”. The US has also updated its national defence strategy to warn Pyongyang that “any nuclear attack by North Korea against the United States or its allies and partners is unacceptable and will result in the end of that regime”.
But Panda dismisses the US commitment as “braggadocio”, recommending that Washington adopt greater ambiguity about the severe consequences that would follow nuclear use by Pyongyang.
“We don’t make these types of threats against our other nuclear adversaries, including Russia and China,” he says. “We are lying to ourselves if we think that is credible.”
Choi agrees. “It is pure hubris for the US always to talk about deterring North Korea without acknowledging that North Korea has itself acquired the capabilities to deter the US.”
When asked if the US would follow through with its commitment to end the regime in the event of North Korean nuclear use, South Korean nuclear envoy Kim Gunn says: “That’s what they said. So when it is said, don’t try to test it.”
As well as a “kill chain” policy of pre-emptive strikes in the event of an imminent attack, South Korea is also publicly committed to an escalatory response as part of its “massive punishment and retaliation” doctrine.
The policy of responding with up to three times the force of the initial attack was developed after a North Korean artillery bombardment in 2010 of South Korean troops stationed on Yeonpyeong island near the disputed western maritime border between the two Koreas.
Choi argues that South Korea’s hardline stance has been vindicated by the fact that North Korea has not attempted an attack of comparable severity since Yeonpyeong island. “Ambiguity is often overrated,” Choi adds.
But he acknowledges that there is an “irreconcilable tension” between the US and its east Asian allies that could yet emerge if a similar incident were to occur in 2023.
“South Korea fears being abandoned by the US in the event of a conflict, while the US fears being dragged into a conflict by South Korea,” says Choi. “Washington needs to reassure South Korea but in moments of crisis also feels the need to restrain it. The tension can be managed, but it will always be there.”
Neither South Korea nor Japan are backing down in the face of North Korean provocations.
In November, South Korea conducted a test of its new long-range surface-to-air missile interceptor system, or L-SAM, while Japan also successfully tested its new Standard Missile-3 ballistic missile interceptor system.
The tests, conducted within a few days of one another, followed a trilateral summit in Cambodia between South Korean president Yoon Suk-yeol, Japanese prime minister Fumio Kishida and US president Joe Biden, at which they pledged to intensify real-time information sharing and co-operation in response to the growing North Korean missile threat.
The senior US official says North Korea’s aggressive actions and rhetoric had made it easier to deepen trilateral engagement with its east Asian allies, describing it as a “striking” change.
“I cannot think of a period . . . where we have been as closely lashed up and synced with [South Korea] and Japan as the past two years,” the official says.
But the two countries are also seeking to bolster their own independent defence capabilities, amid fears that American voters could elect a future leader who does not share Biden’s commitment to east Asia’s defence.
“It is not unreasonable for the South Koreans to be concerned about abandonment, given that President Trump was talking about pulling US troops out of South Korea just a few years ago,” says Sue Mi Terry, noting that South Korea and Japan are also concerned about the challenge posed by an increasingly assertive China.
Japan’s new national security strategy, which will be backed up by a ¥43tn ($322bn) defence budget, envisages the development of a new “counter-strike” capability that could allow it to attempt to destroy enemy missiles before they launch.
Japanese government officials say this counter-strike capability would justify Tokyo’s deeper involvement in discussions with US and South Korea regarding North Korea. But Seoul has privately expressed concerns that Tokyo is set to acquire the ability to trigger a conflict in the Korean Peninsula.
For US policymakers, a more pressing concern is whether failure sufficiently to reassure South Korea of its reliability as an ally will lead to Seoul deciding to acquire an independent nuclear weapons capability of its own, potentially forcing Japan to follow suit.
Go Myong-hyun, senior fellow at the Asan Institute for Policy Studies in Seoul, says US officials have succeeded, for the time being, in convincing their Korean counterparts that there is still a “range of options that needs to be exhausted first”.
He adds that South Korea and the US should not abandon their joint military exercises and displays of strength, no matter how much it upsets the North Korean regime. “It is imperative that the North Koreans reach the conclusion that the possession of nuclear weapons will do nothing to help them achieve their political goals,” Go says.
In Ankit Panda’s view, however, the fundamental problem is that the US and its allies are using the threat of punishment to deter North Korea from using its nuclear weapons, while simultaneously attempting to compel Pyongyang to give them up altogether — a lack of coherence that he says amounts to “strategic malpractice”.
That raises the uncomfortable question of whether Washington, Seoul and Tokyo can ever seriously engage with North Korea on reducing the risks of a conflict as long as they continue to insist that their ultimate goal is North Korea’s denuclearisation.
Kim Gunn, South Korea’s nuclear envoy, insists that Kim Jong Un will eventually return to the negotiating table: “They are more isolated diplomatically, and at the same time their economic situation is worse and worse. As time goes by, what [other] option does North Korea have?”
But Jeongmin Kim of NK Pro questions whether time is really on the side of the US and its allies, noting Kim’s proven willingness to allow his people to suffer while pressing on with his nuclear weapons programme.
“The classic cycle is that North Korea builds capabilities so as to give itself leverage for future negotiations,” she says. “This time, however, Kim Jong Un appears determined to force the world to recognise North Korea as a nuclear weapons state at all costs — and he has his own schedule.”